Email. Sophos v16.5
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You can upload a customized HTML and PDF template when editing or adding a template on the Protect >
Wireless > Hotspots page in the section Hotspot Customization (upload is only available if the customization type
Full is selected).
Figure 416: Download Templates
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
From the Email tab, you can configure SMTP/S, POP/S and IMAP/S settings, Email Security Policies, Secure PDF eXchange (SPX) and Data Control.
The device offers comprehensive Email Security, preventing sophisticated forms of zero-hour threats and blended attacks involving spam, botnets, phishing, spyware and more. The basic email protection configuration includes:
• Creating policies to allow or deny email traffic to and from your Email Server.
• Apply Spam, Malware, Data and File protection on email traffic.
• SPX
• configuring an email threshold size for scanning
• specifying action to be taken if a virus is detected
• blocking mails based on sender or recipient
• blocking mails with certain file types.
SMTP Deployment Modes
SF can be deployed in Two (2) Modes:
• Legacy Mode
• MTA Mode
Legacy Mode
In Legacy Mode, SF acts as a transparent proxy that scans emails for malware and spam, applies SPX Encryption and
Data Protection. Refer to the following guides to see how SF can be configured to scan email traffic in Legacy Mode:
MTA Mode
In MTA Mode, SF acts as a Mail Transfer Agent. A Mail Transfer Agent (MTA) is a service that is responsible for receiving and routing emails to their specified destinations.
Deploy SF in MTA Mode when you want it to perform actual routing of emails as compared to Legacy Mode where
SF only forwards the email traffic as a proxy.
In MTA Mode, SF performs the following functions:
• Performs relaying and routing of emails. You can configure relaying of emails from Email > Relay Settings.
• Protects multiple Email Servers using SMTP Policies. From Email > Policies > SMTP Policies, you define the kind of protection you want to apply on each of your Email Domains.
• Displays email messages that are either waiting or failed to be delivered in the Email > Mail Spool.
• Displays logs for all the emails processed by the Device from Email > Mail Logs.
Pocket Guides
•
Protect Internal Email Server - Legacy Mode
•
Protect Internal Email Server - MTA Mode
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•
Protect Cloud-hosted Email Server - MTA Mode
MTA Mode
Policies
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This page allows configuration of SMTP Route and Scan Policies, SMTP Malware Scan Policies, SMTP Spam Scan
Policies and POP-IMAP Scan Policies:
• SMTP Route and Scan Policies (MTA Mode)
• SMTP Malware Scan Policies (Legacy Mode)
• SMTP Spam Scan Policies (Legacy Mode)
• POP3-IMAP Scan Policies (MTA and Legacy Mode)
SMTP Route and Scan Policies
SMTP Route and Scan policies appear only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
Device allows you to create SMTP Route and Scan policies which can be used to protect multiple Domains on your internal Email Server(s). Using these policies, device protects the server(s) from remote attacks and additionally provide powerful virus scanning, email encryption and email filtering services.
Click Add Policy and then SMTP Route & Scan to add a new policy. To update an existing policy, click the desired policy.
SMTP Malware Scan Policies
SMTP Malware Scan policies appear only when Legacy mode is enabled. The device acts as a transparent proxy.
SMTP Malware Scan policies allow you to define action to be taken on emails if they are virus-infected or contain a protected attachment. Based on the action defined in rule, such emails can be delivered as they are, dropped, or cleaned and then delivered or quarantined.
A Malware Scan policy defines:
• whether to quarantine the email
• whether sender, receiver or administrator are to be notified
• whether to block the email containing a specified file type
• what action is to be taken if email is infected or contains a protected attachment: deliver as it is, drop, clean and then deliver
Note: You can also view the Quarantine from Protect > Email > SMTP Quarantine page.
A default SMTP Malware Scan policy named default-smtp-av is pre-configured in the device and applied to all
SMTP traffic as soon as you subscribe to the Email Protection Module. We recommend that you create separate rules fine-tuned to your specific network requirements to minimize the possibility of threats.
Click Add Policy and then SMTP Malware Scan to add a new policy. To update an existing policy, click the desired policy.
SMTP Spam Scan and POP-IMAP Scan Policies
SMTP Spam Scan policies appear only when Legacy mode is enabled.
POP-IMAP Scan policy is available in both MTA and Legacy modes.
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When you subscribe to the Email Protection Module, SMTP Spam Scan and POP-IMAP Scan policies can be configured for particular senders and recipients.
A policy defines the action to be taken if an email is detected as Spam, Probable Spam, part of Virus Outbreak or
Probable Virus Outbreak.
To reduce the risk of losing legitimate messages, the Spam Quarantine repository (a storage location) provides administrators with a way to automatically quarantine emails that are identified as spam. This helps in managing spam and probable spam quarantined mails so that the user can take appropriate actions on such emails.
A default POP-IMAP Scan policy named default-pop-av is pre-configured in the device and applied to all POP3/S and IMAP/S traffic so that whenever a virus gets detected in an email, the virus-affected attachment is stripped from the email and the email body is replaced with a notification message.
Detection of Spam attributes
The device uses Content Filtering, and premium and standard Realtime Blackhole Lists (RBLs) to check for the spam attributes in SMTP/S, POP3/S and IMAP/S emails:
• Premium
• Standard
RBL is a list of IP Addresses whose owners refuse to stop the proliferation of spam, that is, owners who are responsible for spam or are hijacked for spam relay. The device checks each RBL for the connecting IP Address. If the IP Address matches one on the list, then the specified action in the policy is taken.
Add SMTP Route and Scan Policy
SMTP Route and Scan policies appear only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
SMTP route and scan policy allows you to protect emails from spam and malware, to SPX-encrypt emails and to provide data and file protection.
1. Go to Protect > Email > Policies and click Add Policy. Click SMTP Route & Scan.
2. Enter the Name.
3. Enter the Domains and Routing Target details.
Protected Domain
Select the domains. The policy applies to emails to and from the selected domains. To add a new domain, click Create New.
Emails received by users of the protected domains are Inbound Emails.
Emails sent out by users of the protected domains are Outbound Emails.
Emails sent among users of protected domains are Internal Emails.
Route By
Select the email server to forward the emails to. Select from the following server types:
Available Options:
Static Host: From the Host List, select the static IP addresses of the internal email servers. If the first host in the selected list is not reachable, the device forwards emails to the next host until it reaches the end of the list. To create a new host, click Create.MX: Select to route emails based on
MX records.
Global Action
Select the action.Accept: Accepts all emails to the specified domains. You can apply SPX encryption on outbound emails by selecting the SPX Template from the drop-down list.Reject:
Rejects all emails to the specified domains. Sender is notified.
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Figure 417: Domains and Routing Target
4. Turn on Spam Protection.
You can enable protection for inbound and outbound spam, virus outbreak and blacklisted sender IP addresses through RBLs. Select the action to be applied to spam and probable spam emails.
Available Actions:
• None
• Warn: Delivers the email to the recipient after adding a prefix to the subject. Specify the prefix in Prefix
Subject.
• Quarantine
• Drop: Drops the email without sending a notification to the sender.
Default: Drop
Figure 418: Spam Protection
5. Turn on Malware Protection.
Scanning
Select the scanning action.
Available Actions:
Disable: Emails are not scanned. Enable: Emails are scanned by the device's anti-virus engine.
Note:
In Sophos Firewall XG105, Cyberoam CR500iNG, and Sophos UTM SG105, and higher models, Enable is replaced by the following options.
Single Anti-Virus: The primary anti-virus engine scans the emails.
Dual Anti-Virus: The primary and secondary engines scan emails sequentially.
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Select the Primary Anti-Virus Engine from Protect > Email > General Settings >
Malware Protection.
Detect zero-day threats with Sandstorm (Sandstorm Module required)
Enable to send emails for Sandstorm analysis. Emails found clean by Sandstorm will be delivered to the recipient(s) while selected action will be applied on those found malicious.
Note: Cannot implement Sandstorm with Single Anti-Virus Scanning, if Avira is the
Primary Anti-Virus Engine. You can update it from Protect > General Settings >
Malware Protection or Configure > Configure > System Services > Malware
Protection.
Scanned File Size (available if Detect zero-day threats with Sandstorm is enabled)
Enter the size of files that can be analyzed by Sandstorm. Files with size greater than that will not be analyzed.
Anti-virus Action
Select the action to be taken against malicious emails.
Available Actions:
• None
• Warn: Delivers the email to the recipient after adding a prefix to the subject. Specify the prefix in Prefix Subject.
• Quarantine
• Drop: Drops the email without sending a notification to the sender.
Notify Sender
Select to notify the sender about the infected email.
Quarantine unscannable content
Select to quarantine emails that could not be scanned. These include corrupt, encrypted, compressed files, oversized emails, and emails not scanned due to an internal error.
Figure 419: Malware Protection
6. Turn on File Protection to filter specific attachments.
Block File Types
Select the type of attachments you want to block. The corresponding MIME headers populate the
MIME Whitelist.
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To select more than one file type, press Ctrl+Shift.
The device contains a default list of file types with the relevant file extensions.
Refer to Email > ... > File Type to view the list of file extensions.
Select All to block emails with an attachment.
Select None to allow emails with an attachment.
MIME White List
Select the MIME headers to be allowed during the malware scan. Unselected headers are blocked.
Drop Message Greater Than
Enter the maximum file size (in KB) to be scanned by the device. Larger emails are dropped.
Default: 51200 KB
Figure 420: File Protection
7. Turn on Data Protection. (applicable only to outbound emails)
Data Control List
Select the list to be applied to scan emails for sensitive information.
Data Control Lists (DCL) can be created from the pre-configured Sophos Content Control List
(CCL), which provides common financial and personally identifiable data types, like credit card numbers, social security numbers, postal addresses, or email addresses.
You can create a list from Protect > Email > Data Control List.
Data Control List Action
Select the action to be taken against emails containing sensitive information.
Available Actions:
Accept: Accepts the email and delivers it to the recipient.
Accept with SPX: Accepts and SPX-encrypts the email before delivering it to the recipient. Select the SPX Template to be applied to the email. You can create
Email > Encryption.
Drop: Drops the email without sending a notification to the sender.
Notify Sender
Select to notify the sender that the email contains sensitive information.
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Figure 421: Data Protection
Add POP-IMAP Scan Policy
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
Add a POP-IMAP scan policy to detect incoming and outgoing spam in POP/S and IMAP/S traffic.
1. Go to Protect > Email > Policies and click POP-IMAP Scan.
2. Enter a Name for the policy.
3. Enter email address or domain group details.
Sender
To specify the sender email addresses, select from the following options:
Contains: Specify the keywords to be matched with the senders' email addresses. Example:
If you specify the keyword 'mail', the rule applies to senders' email addresses such as [email protected], [email protected].
Equals: Specify the senders' exact email addresses.
To add a list of keywords or email addresses, click Create New.
Recipient
To specify the recipient email addresses select from the following options:
Contains: Specify the keywords to be matched with the recipient email addresses. Example:
If you specify the keyword 'mail', the rule applies to recipient email addresses such as [email protected], [email protected].
Equals: Specify the recipients' exact email addresses.
To add a list of keywords or email addresses, click Create New.
Figure 422: Email Address/Domain Group
4. Select from the following Filter Criteria based on which the specified action is to be taken:
Inbound Email is
Select from the following options:
Spam Probable Spam Virus Outbreak Probable Virus Outbreak
Source IP/Network Address
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Sender's IP address matches the specified IP address.
Message Size
Sender's email size matches the specified restriction of message size.
Message Header
Select from the following message headers to match the specified keyword:
Subject From To Other
Select the type of keyword match from the following options:
Contains: Specify the keywords to be matched with the message header.
Equals: Specify the exact match to the actual headers.
None
Select to create a policy between specific senders and recipients without imposing any other condition.
Figure 423: Filter Criteria
5. Select the action.
Action
Action to be taken from the following options:
Available Options:
Accept: Email is accepted and delivered to the intended recipient. Prefix Subject: Email is accepted and delivered to the intended recipient after adding a prefix to the subject line. Specify the prefix in the To field. You can set the prefix to indicate the filter criteria.
Example:
Original subject line: Test mail
Tagged content: Probable Spam
Recipient receives email with the subject line: 'Probable Spam: Test mail'
6. Click Save.
Data Control List
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
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This feature is available in Cyberoam Models CR15iNG and above, and all Sophos UTM and Sophos Firewall
Models.
The Data Protection (DP) feature under Email > Policies > SMTP Policies allows you to reduce accidental data loss from workstations by monitoring and restricting the transfer of files containing sensitive data. Accidental data loss is commonly caused by employees mishandling sensitive data. For example, a user sends a file containing sensitive data home via email (SMTP). DP scans outgoing emails including subject line, message body and attachments for sensitive or confidential information. Based on the outcome, the email can be encrypted using SPX encryption, or the email can be rejected or sent.
Data Control List are created by selecting one or more Sophos Content Control List (CCL). CCLs provide expert definitions for common financial and personally identifiable data types, for example, credit card numbers, social security numbers, postal addresses, or email addresses. Advanced techniques, such as checksums, are used in Sophos
CCLs to increase the accuracy of sensitive data detection.
Add a Data Control List
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This feature is available in Cyberoam Models CR15iNG and above, and all Sophos UTM Models.
The Add Data Control List page is used to configure a list used in the Data Protection section in Email >
Policies > SMTP Policies, to scan and detect confidential data in Email traffic and take appropriate action.
1. Go to Email > Data Control List and click Add.
2. Enter list details.
Name
Specify a name to identify the Data Control List.
CCLs
Select one or more CCLs (Content Control List) to be added to the list.
Filter the CCLs based on Type or Region.
Figure 424: Data Control List
3. Click Save.
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SMTP Quarantine
SMTP Quarantine is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The SMTP Quarantine allows you to filter the quarantined emails. The page displays all the emails quarantined by the device if they are found to be:
• From a blocked Source IP Address
• Destined to a blocked Destination IP Address
• Virus-infected
• Oversized
• Containing a Blocked Header
• Containing unscannable content or a protected attachment
• blocked by an RBL
• blocked by a Data Protection (DP)
• Spam
• Found malicious by Sandstorm
• quarantined due to any other reason
Use the filter to search for mails from the list of quarantined emails.
The filter result displays a list of all the quarantined emails based on the filter criteria.
Total utilization displays the percentage of the quarantine area used by quarantined emails. Once the quarantine repository is full older emails are purged.
Quarantine Digest
The Quarantine Digest is an email containing a list of quarantined emails filtered by the device and held in the user's quarantine area. If configured, the user receives a Quarantine Digest as per the frequency set in Email > Quarantine
Digest. The digest also provides a link to the User Portal from where the user can access quarantined emails and take the required action.
Releasing Quarantined Email
Either the Administrator or the user can release the quarantined Emails. Administrator can release the quarantined
Emails from the Quarantine Area while the user can release them from his User Portal. Released quarantined
Emails are delivered to the intended recipient’s inbox. The Administrator can access the Quarantine Area from
Email > SMTP Quarantine, while user can logon to the User Portal and access the Quarantine Area from SMTP
Quarantine. If Quarantine Digest is configured, user will receive Digest of the quarantined mails as per the configured frequency.
Note:
• Virus-infected emails and the emails found malicious by Sandstorm cannot be released.
• To delete Sandstorm related emails, you need Read-Write permission for Sandstorm Activity.
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Figure 425: SMTP Quarantine
Mail Spool
Mail Spool appears only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in
Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The mail spool displays emails that are either waiting for delivery or have returned an error. Use the options to filter the records displayed according to the date range specified.
Start Date/End Date
Specify a date range for the filter.
Default: Current day
Recipient Domain
Enter the recipient domain for which emails are to be displayed.
Status Filter
Select from the following filters to display the emails that are:
• Queued
• Failed
• SPX Blocked: Waiting for recipient to generate password (when SPX password type is configured as Specified by Recipient).
• Frozen: Frozen after three days of failed retries by the device.
• Sophos Sandstorm: Waiting for Sandstorm analysis.
Default: All filters selected
Note: To delete or retry sending Sandstorm related emails, you need Read-Write permission for Sandstorm
Activity.
To apply the selected settings, click Filter.
To reset the filter options, click Clear.
Select Auto-Refresh to automatically refresh the list every second. Clear this option to delete email(s) in the list or to retry sending emails that have resulted in an error.
Mail Logs
Mail Logs appears only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in
Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This page displays the logs for all the emails processed by the Device.
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Start Date/End Date
Select the start and end date during which the message has been processed.
Recipient Domain
Specify the Recipient Domain whose emails you want displayed.
Result Filter
Select which type of message will be displayed.
• Delivered: Successfully delivered emails.
• Rejected: Emails discarded by the Device for which Sender is notified.
• Dropped: Emails discarded by the Device for which Sender is NOT notified.
• Quarantined: Quarantined emails.
• Bounced: Emails automatically discarded by the Device after multiple failed delivery attempts.
• Deleted: Emails that have been manually deleted.
Reason Filter
Filter logs of emails for the following reasons:
• Malware-infected
• Spam
• Contain a blocked file/attachment.
• Contain unscannable content or a protected attachment
• Blocked by a Data Protection (DP)
• SPX-encrypted
• Undelivered and SPX-encrypted
• Blocked by an RBL
• Found malicious by Sandstorm
• Blocked for any other reason
Filter
Click to apply filter on the displayed logs.
Clear
Click to reset the filter options. The default options display the current day as the Start and End Date and all filters are selected.
Figure 426: Mail Logs
Encryption
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SPX Encryption is available in Sophos Firewall XG105 and higher models, Cyberoam CR25iNG and higher models, and all Sophos UTM Models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
What is SPX Encryption?
SPX (Secure PDF Exchange) encryption is a next-generation version of email encryption. It is clientless and extremely easy to set up and customize in any environment. Using SPX encryption, email messages and any attachments sent to the Device are converted to a PDF document, which is then encrypted with a password. You can configure the Device to allow senders to select passwords for the recipients, or the server can generate the password for the recipient and store it for that recipient, or the server can generate one-time passwords for recipients.
When SPX encryption is enabled, there are two ways in which emails can be SPX encrypted:
• The user can download the Sophos Outlook Add-in from User Portal. After having it installed, an Encrypt button is displayed in the Microsoft Outlook user interface. To encrypt a single message, the user needs to click the
Encrypt button and then write and send the message.
Note:
If you do not use Outlook you can also trigger SPX encryption by setting the header field
X-Sophos-SPX-Encrypt to "yes".
• In the Data Protection feature, you can enforce SPX encryption of Emails containing sensitive data (see Email >
Policies > SMTP Policy).
The encrypted message is then sent to the recipient's mail server. Using any PDF reader, the recipient can decrypt the message with the password that was used to encrypt the PDF. SPX-encrypted email messages are accessible on all popular smartphone platforms that have native or third-party PDF file support, including Android, iOS, Blackberry and Windows Mobile devices.
The SPX-encrypted email contains a Reply button which links to the SPX Reply Portal. Using the SPX Reply Portal, the recipient is able to answer to the email in a secure way.
SPX Configuration
Default SPX Template
Select the SPX Template to be used by default. The Default Template is used if any user explicitly
SPX-encrypts an email and no template is selected in the Content Scanning Rule.
The user can SPX-encrypt an Email by:
• Manually setting the Email header X-Sophos-SPX-Encrypt to "yes".
• Installing the Sophos Outlook Add-on and clicking Encrypt before sending the Email.
If the Default SPX Template is set to None, then SPX encryption is not applied to Email.
Allow Secure Reply for
Enter the maximum time (in days) in which recipient can securely reply to an SPX-encrypted email using the SPX Reply Portal.
Keep Unused Password for
Enter the expiry time in days of an unused password.
For example, if Keep Unused Password for is set to 3 days, the password will expire at 0 o'clock 3 days after being generated if no SPX encrypted message has been sent for a specific recipient.
Default: 30 days
Allow Password Registration for
Enter the time in days after which the link to Password Registration Portal expires.
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Default: 10 days
Send Error Notification To
Specify whom to send a notification when an SPX error occurs. You can send the notification to the sender or you can send no notification at all. Error messages will always be listed in the SMTP log.
Figure 427: SPX Configuration
SPX Portal Settings
Host Name
Enter the IP Address or Domain on which the Password Registration Portal is hosted.
Allowed Network(s)
Enter the networks from which password registration requests will be accepted.
Port
Enter the port on which the SPX Password Registration Portal should listen.
Default: 8094
Figure 428: SPX Portal Settings
SPX Password Reset
Reset Password for
Enter the Email Address for the recipient for whom you want to reset the password. New SPX email to this address requires the recipient to obtain a new password from the sender.
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Figure 429: Password Reset
SPX Templates
The SPX template defines the layout of the PDF file, password settings and recipient instructions. You can also define different SPX templates. So, if you are managing various customer domains, you can assign them customized SPX templates containing, for example, different company logos and texts.
Figure 430: SPX Templates
Add SPX Templates
SPX Encryption is available in Sophos Firewall XG105 and higher models, Cyberoam CR25iNG and higher models, and all Sophos UTM Models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This page allows you to define new SPX Templates or modify existing templates.
1. Go to Protect > Email > Encryption > SPX Templates and click Add.
2. Enter parameter values for the following basic settings.
Name
Specify the name to uniquely identify the template. The name should be a string containing alphanumeric and special characters EXCEPT forward slash (/), backslash (\), comma (,), double quote (") and single quote (').
Description
Specify details of the template.
Organization Name
Specify the organization name to be displayed on notifications concerning SPX sent to the administrator or the email sender, depending on your settings.
PDF Encryption
Select the encryption standard of the PDF file.
Page Size
Select the page size of the PDF file.
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Figure 431: General Settings
3. Enter Password Settings.
Password Type
Select how you want to generate the password for accessing the encrypted email message. The sender always has to take care of transferring the password in a safe way to the recipient, unless you select Specified by recipient.
Available Options:
Specified by Sender:
If you select this, the email sender should provide the password. The sender has to enter the password into the Subject field, using the following format:
[secure:<password>]<subject text> where <password> is the password to open the encrypted PDF file and <subject text> is the random subject. Of course, the password will be removed by the Device before the email is sent to the recipient.
Generated one-time password for every email:
The Device automatically creates a new password for each affected email. An email notification is mailed to the sender containing instructions and the one-time generated password.
The HTML content of this Email can be customized from Notification Subject and Notification
Body. You can reset to the default content by clicking Reset .
Generated and stored for recipient:
The Device automatically creates a recipient-specific password when the first email is sent to a recipient. This password will be sent to the sender. With the next email, the same password is used automatically. The password will expire when it is not used for a configured time period, and it can
be reset by the administrator, see
.
The HTML content of this Email can be customized from Notification Subject and Notification
Body. You can reset to the default content by clicking Reset .
Specified by recipient:
If you select this, the email recipient should provide the password. The recipient receives an email notification containing a link leading to the Password Registration Portal to register a password and the Sender receives a failure notification. After registration, the recipient is able to view the current encrypted mail and any future encrypted mails using the same password from this or other senders from the same organization.
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Note: The Recipient's password generated via Specified by recipient method and
Generated and stored for recipient are mutually exclusive. The recipient will have to use the respective password when email is received after SPX Encryption using different methods.
Figure 432: Password Settings
4. Specify Recipient Instructions:
Instructions for Recipient
The body of the email that is sent from the Device to the email recipient containing instructions concerning the encrypted email. Simple HTML markup and hyperlinks are allowed. You can also use variables, e.g.,
%%ORGANIZATION_NAME%%
Tip: The Default SPX Template on this tab contains all available variables and gives a useful example of recipient instructions. The variables used are:
• ENVELOPE_TO: The recipient for whom the password is generated.
• PASSWORD: The password to open SPX encrypted Email
• ORGANIZATION_NAME: The name provided in the Organization Name field.
• SENDER: The sender of the email.
• REG_LINK: The link to the Registration Portal for registering the password.
Figure 433: Recipient Instructions
5. Enable SPX Portal Settings
Enable SPX Reply Portal
Click to enable users to securely reply to SPX-encrypted emails using the SPX Reply Portal. You also have the option to Include Original Body into Reply.
Figure 434: SPX Portal Settings
General Settings
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This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
Email Configuration allows you to configure the general settings Email traffic. This page contains the following sections.
SMTP Deployment Mode
MTA mode is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
Click button to switch to MTA/Legacy Mode.
In MTA Mode, Device acts as a Mail Transfer Agent (MTA). In Legacy Mode, Device acts as a transparent proxy.
When acting as an MTA, Device is responsible for routing Emails to and from the protected Email Server(s). In this state Device allows you to:
• configure relay of inbound and outbound Emails from Email > Relay Settings.
• set up multiple SMTP Profiles to protect multiple Domains on your internal Email Server or multiple Email
Servers from Email > Policies > SMTP Policies.
• view email messages that are either waiting for delivery or have produced an error in the Email > Mail Spool.
• view the logs for all the emails processed by the Device from Email > Mail Logs.
Default: MTA Mode is enabled.
Note:
• On enabling MTA Mode, a firewall rule to allow SMTP/SMTPS traffic is automatically created.
• If you have migrated from CyberoamOS to SFOSv16 OR SFOSv15 to SFOSv16, Legacy Mode will be enabled by default.
Figure 435: SMTP Deployment Mode
Banner Settings
Append Banner to All Outbound Messages
Enable to add a banner at the end of all outgoing Email messages.
The banner is appended ONLY when SMTP and SMTPS Scanning is enabled in the relevant
Business Application Policy(s).
Email Banner
Specify a banner to be added to all outgoing Emails. Only text banners are allowed.
Example:
This email contains confidential information. You are not authorized to copy the contents without the consent of the sender. Please do not print this email unless it is absolutely necessary. Spread environmental awareness.
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Figure 436: Banner Settings
SMTP Settings
SMTP Hostname
Specify the SMTP hostname to be used in HELO and SMTP banner strings. By default, Device uses
'Sophos' as hostname.
Note: For Legacy Mode, this hostname is applicable only to system-generated notification emails.
Don't Scan Emails Greater Than
Specify maximum file size (in KB) for scanning. Files exceeding this size received through SMTP/S will not be scanned.
Default - 1024 KB
Specify 0 to increase the default file size scanning restriction to 51200 KB.
Action for Oversize Email
Specify the action for Oversize Emails.
Available Options
Accept: All the oversize mails are forwarded to the recipient without scanning.Reject: All the oversize mails are rejected and sender is notified.Drop: All the oversized mails are dropped, without notifying the sender.
Bypass Spam Check for SMTP/S Authenticated Connections (Available in Legacy Mode only)
Enable to bypass Spam Scanning for Email messages received over SMTP/S connections authenticated by the Email Server.
Verify Sender's IP Reputation
Click to verify the reputation of the sender IP Address. When enabled, the Device dynamically checks the sender’s IP Address of all Emails. If the IP Address is found to be responsible for sending spam email or malicious contents, the Device takes action as per the configured Scanning
Rules.
If enabled, specify an action for Confirmed Spam Emails and Probable Spam Emails.
Available Options
Accept: All the spam Emails are forwarded to the recipient after scanning as per the configuration.
Reject: All the spam mails are rejected and a notification is sent to the Email sender. Drop: All the spam mails are dropped, without notifying the sender.
As it is a global option, if spam scanning is enabled, all the mails will first be subjected to IP
Reputation filtering followed by filtering based on actions configured in the spam policy.
Default - Disable
SMTP DoS Settings
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Enable to configure SMTP DoS Settings which protect the network from SMTP DoS Attacks.
If this is enabled, specify values for Maximum Connections, Maximum Connections/Host,
Maximum Emails/Connection, Maximum Recipients/Email, Email Rate per Minute/Host and
Connections Rate per Second/Host.
Maximum Connections (Available if SMTP DoS Settings Enabled)
Specify maximum number of connections that can be established with the Email Server.
Default - 1024
Acceptable Range - 1 - 20000
Maximum Connections/Host (Available if SMTP DoS Settings Enabled)
Specify maximum number of connections allowed to the Email Server from a particular host.
Default - 64
Acceptable Range - 1 - 10000
Maximum Emails/Connection (Available if SMTP DoS Settings Enabled)
Specify maximum number of Emails that can be sent in a single connection.
Default - 512
Acceptable Range - 1 - 1000
Maximum Recipients/Email (Available if SMTP DoS Settings Enabled)
Specify maximum number of recipientsfor a single Email.
Default - 100
Acceptable Range - 1 - 256
Email Rate per Minute/Host (Available if SMTP DoS Settings Enabled)
Specify number of Emails to be sent from a particular host in one minute.
Default - 512
Acceptable Range - 1 - 20000
Connection Rate per Second/Host (Available if SMTP DoS Settings Enabled)
Specify number of connections allowed to the Email Server from a particular host in one second.
Default - 8
Acceptable Range - 1 - 20000
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Figure 437: SMTP Settings
POP/S and IMAP/S Settings
Don't Scan Emails Greater Than
Specify maximum file size (in KB) for scanning. Files exceeding this size received through POP/
IMAP will not be scanned.
Default - 1024 KB
Specify 0 to increase the default file size restriction to 10240 KB.
Recipient Headers
Specify Header value to detect recipient for POP3/IMAP.
Default - Delivered-To, Received, X-RCPT-TO
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Figure 438: POP/S and IMAP/S Settings
SMTP TLS Configuration
TLS Certificate
Select the CA Certificate or Server Certificate for scanning SMTP traffic over SSL from the available options.
Available Options
Default ApplianceCertificate SecurityAppliance_SSL_CA List of custom CA Certificates and
Server Certificates, if added. You can create the custom CA Certificate from Certificates >
Certificate Authorities and custom Server Certificate from Certificates > Certificates.
Allow Invalid Certificate
If enabled, SMTP over SSL connections will be allowed with an invalid certificate from the Email
Server. Disable this option to reject such connections.
Default - Enable
Require TLS Negotiation with Host/Net
Select the remote host (Email Server) or network from available options on whose connections
TLS encryption is to be enforced. In other words, the Device will always initiate TLS-secured connections when Emails are to be sent to selected hosts/networks. If TLS is enforced but connection cannot be established, then Emails to that remote host/network are discarded.
Require TLS Negotiation with Sender Domain
Specify the Sender Domain(s) on whose Email connections TLS encryption is to be enforced.
Sender Domain is the domain of the Email sender. Emails from the specified Sender Domain will be sent over TLS-encrypted connections only. If TLS is enforced but connection cannot be established, then Emails from that sender domain are discarded.
Skip TLS Negotiation Hosts/Nets
Select the remote host (Email Server) or network from available options on whose connections TLS encryption is to be skipped or bypassed. When configured, SMTP connections to selected hosts will be established in clear text and unencrypted.
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Figure 439: SMTP TLS Configuration
POP and IMAP TLS Configuration
TLS Certificate
Select the CA for scanning POP and IMAP traffic over SSL from the available options.
Available Options
DefaultSecurityAppliance_SSL_CAList of custom CAs if added. You can create the custom CA from Certificates > Certificate Authorities.
Allow Invalid Certificate
If enabled, POP and IMAP over SSL connections will be allowed with invalid certificate from the
Mail Server. Disable to reject such connections.
Default - Enable
Figure 440: POP and IMAP TLS Configuration
Email Journaling (Available in Legacy Mode only)
Email being one of the most important communication and business tools in use by organizations, email journaling has become an integral part of every organization.
Using the Device's Email Journaling, the administrator can store all incoming Emails, or Emails for a specific recipient or a group of recipients and thereby keep a close watch over data leakage.
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The device can journal all Emails intended for single or multiple recipients and can forward them to a single administrator or multiple administrators.
This section displays a list of the archivers created and provides options to
,
update the parameters of existing archiver
, or delete the archiver. You can filter the list based on recipient name.
Figure 441: Email Journaling
Spam Check Exceptions
To bypass spam scanning of certain domains, define the domains as Spam Check Exceptions. The page lists all the domains configured to be exempted from spam scanning.
It also provides the options to add a new domain and delete an existing domain.
Figure 442: Spam Check Exceptions
Malware Protection
Malware Protection is available in Sophos Firewall XG105, Cyberoam CR500iNG, Sophos UTM SG105, and higher models.
Sophos Firewall offers dual anti-virus scanning, wherein traffic is scanned by two (2) anti-virus engines. Traffic is first scanned by the primary engine, and then by the secondary engine.
Primary Anti Virus Engine
Select the primary anti-virus engine for traffic scanning. For dual scan, packets are first scanned by the primary engine and then by the secondary engine. For single scan, only the primary engine is used.
Available OptionsSophosAvira
Note: Selecting Avira will disable Sandstorm in all SMTP Policies with Single Anti-Virus Scanning.
Figure 443: Malware Protection
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Advanced SMTP Settings (Available in MTA Mode only)
Reject invalid HELO or missing RDNS
Select this option if you want to reject hosts that send invalid HELO/EHLO arguments or lack
RDNS entries. Select Do strict RDNS checks if you want to additionally reject email from hosts with invalid RDNS records. An RDNS record is invalid if the found hostname does not resolve back to the original IP address.
Scan Outgoing Mails
Enable to scan all outgoing email traffic. Email is quarantined if found to be malware infected, or marked as Spam.
Figure 444: Advanced SMTP Settings
Address Groups
Policies are applied on Email Addresses. To make configuration easier and simpler, the Administrator can group the addresses that require the same scanning policy. The policy applied to the address group is applicable to all the group members. Hence when the group is used in a number of rules, it becomes much easier to add or remove addresses from the group rather than updating individual rules. Hence, just with the one update, the Administrator can re-align the rules.
An Address Group is a grouping by:
• Email Address or Domain
• IP Address
• RBL (Real time black hole List) (applicable only for the spam email)
An address can be a member of multiple groups.
An RBL is a list of IP Addresses whose owners are responsible for spam or are hijacked for a spam relay. These IP
Addresses might also be used for spreading viruses. The Device checks each RBL for the connecting IP Address and the action configured in the policy is taken if the IP Address is found in any of the RBL lists. The Administrator can directly use the two default RBL groups shipped with the Device or update them as per their requirement:
• Premium RBL Services
• Standard RBL Services
The Address Group page displays a list of all the default and custom groups and provides options to add a new group, update the parameters, import addresses in the existing group, or delete the group. You can sort the list based on address group name.
Add Address Group
1. Go to Protect > Email > Address Group and click Add.
2. Enter a name and description.
3. Group Type: Select to add email addresses or domains to the address group.
Available Options:
RBL (IPv4) or RBL(IPv6):
Select to add RBLs of IPv4 or IPv6 addresses or domain names.
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If the connecting IP address is found on the RBL, the device takes the action specified by the relevant policy.
Email Address/Domain:
Select to add the email address or domain name.
Import: Select to upload a CSV or text file.
Manual: Select to add individual email addresses or domains.
Note:
• You can import a maximum of 400 email addresses or domains in a single file.
• Invalid and duplicate entries are not imported.
Figure 445: Address Group
4. Click Save.
Relay Settings
Relay Settings appears only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in
Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
Sophos XG Firewall can be configured to act as an email relay which allows specific hosts to relay (i.e. send) emails through it to specified domains.
Host Based Relay
Allow Relay from Hosts/Networks
Select the hosts/networks which can use SF as an email relay. You can use the Create New link to create a new host. Click Apply to save the configuration.
Note: It is extremely important not to select Any in Allowed Hosts/Networks, because this would result in an open relay, allowing anyone on the Internet to send messages through SF. Spammers will quickly recognize this, leading to massive email traffic. In the worst case, you will be listed on 3rd party spammer blacklists. In most configurations, the only hosts that should be allowed to relay emails are the mail servers in your network.
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Blocked Relay from Hosts/Networks
Specify the hosts/networks that should be blocked by Device. You can use the Create New link to create a new host. Click Apply to save the configuration.
Upstream Host
Allow Relay from Hosts/Networks
Specify the upstream hosts/networks from whom you are to allow inbound emails, typically your
ISP or external MX. You can use Create New link to create a new host.
Block Relay from Hosts/Networks
Specify the hosts/networks whose inbound emails should be blocked by Device. You can use the
Create New link to create a new host.
Note: The "Allow" list for both Host Based Relay and Upstream Host is given higher priority than the
"Block" list. For example, if a host/network appears both in the Allow list and the Block list, SF will allow relay from that host/network.
Authenticated Relay Settings
Enable Authenticated Relay
Enable to allow the authenticated users or groups selected below to use Device as an Email Relay.
Users or Groups
Select the users or groups to be allowed to use Device as an Email Relay. You can use the Create
New link to create a new user or group.
File Types
A file type is a classification that is determined by file extension and MIME header. You can include file types in web policies to control access to files that match the specified criteria. The default file types contain some common criteria and you can create additional types.
Using File Types with Policy Rules
You can create file types to control access to files on a more granular level. For example, you may want to allow access to SQL files but deny access to all other database files. In this case, you would create a file type for SQL files and a policy that specifies the following rules in the following order:
1. Allow access to SQL files
2. Block access to all database files
Add File Type
1. Go to Protect > Web > File Type and click Add.
2. Type a name.
3. (Optional) Select a template.
You can select from predefined or custom file types. If you do not wish to use a template, choose Blank.
4. Specify the file extension and MIME header.
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Figure 446: Add File Type
Quarantine Digest
Quarantine Digest is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The Quarantine Digest is an Email containing a list of quarantined Emails filtered by the Device and held in the user
Quarantine Area. If it is configured, the user receives a Quarantine Digest as per the frequency defined on this page.
The digest also provides a link to the User Portal from where the user can access quarantined Emails and take the required action.
The Quarantine Digest settings can be configured globally for all the users or for individual users. The user receives the Quarantine Digest as per the configured frequency.
The Quarantine Digest provides the following information for each quarantined message:
• Date and time: Date and time when the message was received
• Sender: Email address of the sender
• Recipient: Email address of the receiver
• Subject: Subject of the message
Configuring the Quarantine Digest for All Users
Enable Quarantine Digest
Enable the Quarantine Digest to configure the digest service for all the users.
Email Frequency
Specify the mailing frequency for digest.
Digests can be mailed every hour, every day at configured time, or every week on the configured day and time.
From Email Address
Specify the Email Address from which the email should be sent.
Display Name
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Specify the email sender name. Digest email will be sent with this name.
Send Test Email
Click this and provide an email address to which the message is to be sent for Email Address verification.
Reference User Portal IP
Select Interface/Port IP from the ‘Reference User Portal IP’ dropdown list.
The User Portal link in the digest mail will point to this IP Address. The user can click the link to access his quarantined messages and take the required action. Users who do not come under the specified Interface will have to access the quarantine email directly from their MyAccount.
Change User's Quarantine Digest Settings
Click to change the digest settings of the individual users.
This allows you to select the group and update the Quarantine Digest Setting of group members.
Overriding Quarantine Digest Settings for a Specific User(s)
Click Change User’s Quarantine Digest Settings to change the digest settings for individual users. This opens a new pop-up window named Manage Quarantine Digest, which allows you to search groups and users.
You can individually search for user and user groups.
Select the checkbox against a user to enable the Quarantine Digest. If it is enabled, the configured Quarantine Digest
Settings are applicable for the user.
Figure 447: Quarantine Digest
Legacy Mode
Policies
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This page allows configuration of SMTP Route and Scan Policies, SMTP Malware Scan Policies, SMTP Spam Scan
Policies and POP-IMAP Scan Policies:
• SMTP Route and Scan Policies (MTA Mode)
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• SMTP Malware Scan Policies (Legacy Mode)
• SMTP Spam Scan Policies (Legacy Mode)
• POP3-IMAP Scan Policies (MTA and Legacy Mode)
SMTP Route and Scan Policies
SMTP Route and Scan policies appear only when MTA (Mail Transfer Agent) mode is enabled. MTA mode is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
Device allows you to create SMTP Route and Scan policies which can be used to protect multiple Domains on your internal Email Server(s). Using these policies, device protects the server(s) from remote attacks and additionally provide powerful virus scanning, email encryption and email filtering services.
Click Add Policy and then SMTP Route & Scan to add a new policy. To update an existing policy, click the desired policy.
SMTP Malware Scan Policies
SMTP Malware Scan policies appear only when Legacy mode is enabled. The device acts as a transparent proxy.
SMTP Malware Scan policies allow you to define action to be taken on emails if they are virus-infected or contain a protected attachment. Based on the action defined in rule, such emails can be delivered as they are, dropped, or cleaned and then delivered or quarantined.
A Malware Scan policy defines:
• whether to quarantine the email
• whether sender, receiver or administrator are to be notified
• whether to block the email containing a specified file type
• what action is to be taken if email is infected or contains a protected attachment: deliver as it is, drop, clean and then deliver
Note: You can also view the Quarantine from Protect > Email > SMTP Quarantine page.
A default SMTP Malware Scan policy named default-smtp-av is pre-configured in the device and applied to all
SMTP traffic as soon as you subscribe to the Email Protection Module. We recommend that you create separate rules fine-tuned to your specific network requirements to minimize the possibility of threats.
Click Add Policy and then SMTP Malware Scan to add a new policy. To update an existing policy, click the desired policy.
SMTP Spam Scan and POP-IMAP Scan Policies
SMTP Spam Scan policies appear only when Legacy mode is enabled.
POP-IMAP Scan policy is available in both MTA and Legacy modes.
When you subscribe to the Email Protection Module, SMTP Spam Scan and POP-IMAP Scan policies can be configured for particular senders and recipients.
A policy defines the action to be taken if an email is detected as Spam, Probable Spam, part of Virus Outbreak or
Probable Virus Outbreak.
To reduce the risk of losing legitimate messages, the Spam Quarantine repository (a storage location) provides administrators with a way to automatically quarantine emails that are identified as spam. This helps in managing spam and probable spam quarantined mails so that the user can take appropriate actions on such emails.
A default POP-IMAP Scan policy named default-pop-av is pre-configured in the device and applied to all POP3/S and IMAP/S traffic so that whenever a virus gets detected in an email, the virus-affected attachment is stripped from the email and the email body is replaced with a notification message.
Detection of Spam attributes
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The device uses Content Filtering, and premium and standard Realtime Blackhole Lists (RBLs) to check for the spam attributes in SMTP/S, POP3/S and IMAP/S emails:
• Premium
• Standard
RBL is a list of IP Addresses whose owners refuse to stop the proliferation of spam, that is, owners who are responsible for spam or are hijacked for spam relay. The device checks each RBL for the connecting IP Address. If the IP Address matches one on the list, then the specified action in the policy is taken.
Add SMTP Malware Scan Policy
SMTP Malware Scan policies appear only when Legacy mode is enabled. The device acts as a transparent proxy.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The Add SMTP Malware Scan Policy page allows you to configure scan policy to detect malware in Email traffic and take appropriate action.
1. Go to Email > Policies, click Add policy and then click SMTP Malware Scan.
2. Enter a Name to identify the scan rule.
3. Enter Email Address/Domain Group details.
Sender
Select the sender name from the list of users.
Select Any if the rule is to be applied on all the senders.
You can also add RBLs or list of Email addresses by clicking Create New link.
Recipient
Select the recipient name from the list of users.
Select Any if the rule is to be applied on all the recipients.
You can also add RBLs or list of Email addresses by clicking Create New link.
Figure 448: Email Address/Domain Group
4. Enter Attachment Filter details.
Block File Types
Select file types to be blocked as an attachment to remove all the files that are a potential threat and to prevent virus attacks.
More than one file type can be selected using ctrl/shift keys.
Device contains a default list of File Types, with each Type containing relevant file extensions.
Refer to Email > File Type to view the list of file extensions which can be blocked.
Select All to block Emails with any type of attachments.
Select None to allow Emails with any type of attachments.
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MIME Whitelist
If one or more File Type is selected in Block File Type, this field is populated with the corresponding MIME Headers that belong to selected File Type(s).
Select the MIME Header(s) of the selected File Type(s). Only selected headers are to be allowed while the rest in the selected File Type are to be blocked during Anti-virus scanning of Email attachments.
Figure 449: Attachment Filter
5. Specify Malware Filter details.
Scanning
Select the scanning action.
Available Actions:
Disable: Emails are not scanned. Enable: Emails are scanned by the device's anti-virus engine.
Note:
In Sophos Firewall XG105, Cyberoam CR500iNG, and Sophos UTM SG105, and higher models, Enable is replaced by the following options.
Single Anti-Virus: The primary anti-virus engine scans the emails.
Dual Anti-Virus: The primary and secondary engines scan emails sequentially.
Select the Primary Anti-Virus Engine from Protect > Email > General Settings >
Malware Protection.
Action (Available only if Scanning is enabled)
Enable action to be taken on the mails received, from the available options:Quarantine: If enabled, copies the Email to the quarantine file list. Email is either delivered to recipient or dropped, as per configured Recipient Action.You can view the Email details like sender and receiver of the Email in the Quarantine. Administrator can access the Quarantine from Email > SMTP Quarantine while user can access from their respective User Portal.Notify Sender: If enabled, the original message is withheld by the Device and a notification is sent to the sender informing that the Email was infected. The sender will receive the notification only if the Receiver Action is configured as
Don't Deliver.
Default - Disable
Delivery Option for Infected Attachment/Protected Attachment (Available only if Scanning is enabled)
Recipient Action
Select the action to be taken on the message that is detected to be Infected, Suspicious or includes a
Protected Attachment.
Available Options:
Don't Deliver: Receiver will not receive the message and will also not receive the notification regarding the infected Email.Deliver Original: Receiver receives the original Email.Remover and
Deliver: Infected part of the Email is removed before delivering. Receiver will also receive the
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Note: Protected attachments are not scanned but receiver will be notified, if not specified otherwise.
Notify Administrator
Select the action to notify the Administrator for the message detected to be Infected, Suspicious or includes a Protected Attachment.
Available Options:
Don't Deliver: Administrator will not be notified about the infected Email.Send Original:
Administrator receives the original Email.Remove Attachment: Recipient receives message without attachment and the Administrator receives the notification that the Email attachment was infected and removed before delivering Email.
Note: Protected attachments are not scanned but receiver will be notified, if not specified otherwise.
Figure 450: Malware Filter
6. Click Save.
Add SMTP Spam Scan Policy
SMTP Spam Scan policies appear only when Legacy mode is enabled. The device acts as a transparent proxy.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The Add SMTP Scan Policy page allows you to configure scanning policy to detect incoming and outgoing spam in email traffic and take appropriate action.
1. Go to Email > Policies, click Add Policy and then click SMTP Spam Scan.
2. Enter a Name for the policy.
3. Enter Email Address/Domain Group details.
Sender
Specify Email Address(es) of the Sender(s). You can select from:
Contains: Specify keywords to be matched with Sender Email Addresses. The rule applies to
Address(es) containing those keywords. For example, if the keyword "mail" is specified, the rule will apply to Sender Email Addresses [email protected], [email protected], etc.
Equals: Specify the exact Email Address(es) of the Sender(s).
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You can also add RBLs, a list of Email Addresses or keywords using the Create New link.
Recipient
Specify Email Address(es) of the Recipient(s). You can select from:
Contains: Specify keywords to be matched with Recipient Email Addresses. The rule applies to
Address(es) containing those keywords. For example, if keyword "mail" is specified, the rule will apply to Recipient Email Addresses [email protected], [email protected], etc.
Equals: Specify the exact Email Address(es) of the Recipient(s).
You can also add RBLs, a list of Email Addresses or keywords using Create New link.
Figure 451: Email Address/Domain Group
4. Select the Filter Criteria.
Inbound Email is
All the Emails that are received by the users in their inbox are referred to as Inbound.
If you select Inbound Spam, all the Emails received by the users are scanned for spam and viruses by the Device.
The specified action will be taken if the Device has identified the Inbound Email to be one of the following:
Spam Probable Spam Virus Outbreak Probable Virus Outbreak
Outbound Email is
Emails that are sent by the user in the network to a remote user on another Email system, are referred as Outbound.
If you select Outbound Spam, all the Emails sent by the local users are scanned for spam and viruses by the Device before being delivered.
The specified action will be taken if the Device has identified the Outbound Email to be one of the following:
Spam Probable Spam Virus Outbreak Probable Virus Outbreak
Source IP/Network Address
Specify the action to be taken when the Email sender IP Address matches the specified IP Address.
Destination IP/Network Address
Specify the action to be taken when the Email recipient IP Address matches the specified IP
Address.
Sender Remote Blacklist
Specify the action to be taken when the sender is listed in the specified RBL Group.
Message Size
The specified action will be taken if the Email size matches the specified size.
Message Header
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The specified action will be taken if the message header equals or contains the specified text.
Contains: Specify keywords to be matched with Message Header. The rule applies to Header(s) containing those keywords.
Equals: Specify the exact Header(s) to be scanned.
You can scan message header for Spam in:
Subject: The specified action will be taken if the header contains the matching subject. From: The specified action will be taken if the header contains the matching text in the From address. To: The specified action will be taken if the header contains the matching text in the To address. Other: The specified action will be taken if the matching text is found in the headers.
Data Control List
The specified action will be taken if the message contains data matching with the configured
. You can create Data Protection Policies at Email > Data Control List.
Note: Data Protection is applicable on outbound emails only.
None
Select this to create a rule for email between a specific sender and recipient without any conditions.
You can set actions for SMTP/S and POP/S-IMAP/S mails only on the basis of sender and recipient.
Figure 452: Filter Criteria
5. Select the Action.
Action
Select action to be taken for the SMTP/S traffic.
Available Options:
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Reject: Email is rejected and a rejection notification is sent to the Email sender. Accept (Not
available for Outbound Spam): Email is accepted and delivered to the intended recipient. The
Administrator can bind an SPX Template to this action so that the Email is delivered to the intended recipient after being SPX-encypted.
Note: SPX Encryption is applicable on outbound emails only.
Change Recipient: Email is accepted but is not delivered to the intended recipient for whom the message was originally sent. Email is sent to the recipient specified in the spam policy. Prefix
Subject (Not available for Outbound Spam): Email is accepted and delivered to the intended recipient but after tagging the subject line. The Administrator can bind an SPX Template to this action so that the Email is delivered to the intended recipient after being SPX-encrypted. Tagging content is specified in the To field. You can customize subject tagging in such a way that the recipient knows that the is a spam Email. For Example, Contents to be prefixed to the original subject: ‘Spam notification from the Device –' Original subject: ‘This is a test’ Recipient will receive Email with the subject line: ‘Spam notification from the Device - This is a test’ Drop: Email is rejected but a rejection notification is not sent to the Email sender.
SPX Template
If the action selected is Accept, Prefix Subject or Accept with SPX, select the SPX Template to be applied to the Email. You can create
Note: SPX Encryption is applicable on outbound emails only.
Quarantine
If this is enabled, the device does not deliver Email but copies it to the quarantine file list. You can view the Email details like the sender and recipient in the quarantined file list.
6. Click Save.
Add POP-IMAP Scan Policy
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
Add a POP-IMAP scan policy to detect incoming and outgoing spam in POP/S and IMAP/S traffic.
1. Go to Protect > Email > Policies and click POP-IMAP Scan.
2. Enter a Name for the policy.
3. Enter email address or domain group details.
Sender
To specify the sender email addresses, select from the following options:
Contains: Specify the keywords to be matched with the senders' email addresses. Example:
If you specify the keyword 'mail', the rule applies to senders' email addresses such as [email protected], [email protected].
Equals: Specify the senders' exact email addresses.
To add a list of keywords or email addresses, click Create New.
Recipient
To specify the recipient email addresses select from the following options:
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Contains: Specify the keywords to be matched with the recipient email addresses. Example:
If you specify the keyword 'mail', the rule applies to recipient email addresses such as [email protected], [email protected].
Equals: Specify the recipients' exact email addresses.
To add a list of keywords or email addresses, click Create New.
Figure 453: Email Address/Domain Group
4. Select from the following Filter Criteria based on which the specified action is to be taken:
Inbound Email is
Select from the following options:
Spam Probable Spam Virus Outbreak Probable Virus Outbreak
Source IP/Network Address
Sender's IP address matches the specified IP address.
Message Size
Sender's email size matches the specified restriction of message size.
Message Header
Select from the following message headers to match the specified keyword:
Subject From To Other
Select the type of keyword match from the following options:
Contains: Specify the keywords to be matched with the message header.
Equals: Specify the exact match to the actual headers.
None
Select to create a policy between specific senders and recipients without imposing any other condition.
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Figure 454: Filter Criteria
5. Select the action.
Action
Action to be taken from the following options:
Available Options:
Accept: Email is accepted and delivered to the intended recipient. Prefix Subject: Email is accepted and delivered to the intended recipient after adding a prefix to the subject line. Specify the prefix in the To field. You can set the prefix to indicate the filter criteria.
Example:
Original subject line: Test mail
Tagged content: Probable Spam
Recipient receives email with the subject line: 'Probable Spam: Test mail'
6. Click Save.
Data Control List
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This feature is available in Cyberoam Models CR15iNG and above, and all Sophos UTM and Sophos Firewall
Models.
The Data Protection (DP) feature under Email > Policies > SMTP Policies allows you to reduce accidental data loss from workstations by monitoring and restricting the transfer of files containing sensitive data. Accidental data loss is commonly caused by employees mishandling sensitive data. For example, a user sends a file containing sensitive data home via email (SMTP). DP scans outgoing emails including subject line, message body and attachments for sensitive or confidential information. Based on the outcome, the email can be encrypted using SPX encryption, or the email can be rejected or sent.
Data Control List are created by selecting one or more Sophos Content Control List (CCL). CCLs provide expert definitions for common financial and personally identifiable data types, for example, credit card numbers, social security numbers, postal addresses, or email addresses. Advanced techniques, such as checksums, are used in Sophos
CCLs to increase the accuracy of sensitive data detection.
Add a Data Control List
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This feature is available in Cyberoam Models CR15iNG and above, and all Sophos UTM Models.
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The Add Data Control List page is used to configure a list used in the Data Protection section in Email >
Policies > SMTP Policies, to scan and detect confidential data in Email traffic and take appropriate action.
1. Go to Email > Data Control List and click Add.
2. Enter list details.
Name
Specify a name to identify the Data Control List.
CCLs
Select one or more CCLs (Content Control List) to be added to the list.
Filter the CCLs based on Type or Region.
Figure 455: Data Control List
3. Click Save.
SMTP Quarantine
SMTP Quarantine is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The SMTP Quarantine allows you to filter the quarantined emails. The page displays all the emails quarantined by the device if they are found to be:
• From a blocked Source IP Address
• Destined to a blocked Destination IP Address
• Virus-infected
• Oversized
• Containing a Blocked Header
• Containing unscannable content or a protected attachment
• blocked by an RBL
• blocked by a Data Protection (DP)
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• Spam
• Found malicious by Sandstorm
• quarantined due to any other reason
Use the filter to search for mails from the list of quarantined emails.
The filter result displays a list of all the quarantined emails based on the filter criteria.
Total utilization displays the percentage of the quarantine area used by quarantined emails. Once the quarantine repository is full older emails are purged.
Quarantine Digest
The Quarantine Digest is an email containing a list of quarantined emails filtered by the device and held in the user's quarantine area. If configured, the user receives a Quarantine Digest as per the frequency set in Email > Quarantine
Digest. The digest also provides a link to the User Portal from where the user can access quarantined emails and take the required action.
Releasing Quarantined Email
Either the Administrator or the user can release the quarantined Emails. Administrator can release the quarantined
Emails from the Quarantine Area while the user can release them from his User Portal. Released quarantined
Emails are delivered to the intended recipient’s inbox. The Administrator can access the Quarantine Area from
Email > SMTP Quarantine, while user can logon to the User Portal and access the Quarantine Area from SMTP
Quarantine. If Quarantine Digest is configured, user will receive Digest of the quarantined mails as per the configured frequency.
Note:
• Virus-infected emails and the emails found malicious by Sandstorm cannot be released.
• To delete Sandstorm related emails, you need Read-Write permission for Sandstorm Activity.
Figure 456: SMTP Quarantine
Encryption
SPX Encryption is available in Sophos Firewall XG105 and higher models, Cyberoam CR25iNG and higher models, and all Sophos UTM Models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
What is SPX Encryption?
SPX (Secure PDF Exchange) encryption is a next-generation version of email encryption. It is clientless and extremely easy to set up and customize in any environment. Using SPX encryption, email messages and any attachments sent to the Device are converted to a PDF document, which is then encrypted with a password. You can configure the Device to allow senders to select passwords for the recipients, or the server can generate the password for the recipient and store it for that recipient, or the server can generate one-time passwords for recipients.
When SPX encryption is enabled, there are two ways in which emails can be SPX encrypted:
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• The user can download the Sophos Outlook Add-in from User Portal. After having it installed, an Encrypt button is displayed in the Microsoft Outlook user interface. To encrypt a single message, the user needs to click the
Encrypt button and then write and send the message.
Note:
If you do not use Outlook you can also trigger SPX encryption by setting the header field
X-Sophos-SPX-Encrypt to "yes".
• In the Data Protection feature, you can enforce SPX encryption of Emails containing sensitive data (see Email >
Policies > SMTP Policy).
The encrypted message is then sent to the recipient's mail server. Using any PDF reader, the recipient can decrypt the message with the password that was used to encrypt the PDF. SPX-encrypted email messages are accessible on all popular smartphone platforms that have native or third-party PDF file support, including Android, iOS, Blackberry and Windows Mobile devices.
The SPX-encrypted email contains a Reply button which links to the SPX Reply Portal. Using the SPX Reply Portal, the recipient is able to answer to the email in a secure way.
SPX Configuration
Default SPX Template
Select the SPX Template to be used by default. The Default Template is used if any user explicitly
SPX-encrypts an email and no template is selected in the Content Scanning Rule.
The user can SPX-encrypt an Email by:
• Manually setting the Email header X-Sophos-SPX-Encrypt to "yes".
• Installing the Sophos Outlook Add-on and clicking Encrypt before sending the Email.
If the Default SPX Template is set to None, then SPX encryption is not applied to Email.
Keep Unused Password for
Enter the expiry time in days of an unused password.
For example, if Keep Unused Password for is set to 3 days, the password will expire at 0 o'clock 3 days after being generated if no SPX encrypted message has been sent for a specific recipient.
Default: 30 days
Allow Password Registration for
Enter the time in days after which the link to Password Registration Portal expires.
Default: 10 days
Send Error Notification To
Specify whom to send a notification when an SPX error occurs. You can send the notification to the sender or you can send no notification at all. Error messages will always be listed in the SMTP log.
Figure 457: SPX Configuration
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SPX Portal Settings
Hostname
Enter the IP Address or Domain on which the Password Registration Portal is hosted.
Allowed Network(s)
Enter the networks from which password registration requests will be accepted.
Port
Enter the port on which the SPX Password Registration Portal should listen.
Default: 8094
Figure 458: SPX Portal Settings
SPX Password Reset
Reset Password for
Enter the Email Address for the recipient for whom you want to reset the password. New SPX email to this address requires the recipient to obtain a new password from the sender.
Figure 459: Password Reset
SPX Templates
The SPX template defines the layout of the PDF file, password settings and recipient instructions. You can also define different SPX templates. So, if you are managing various customer domains, you can assign them customized SPX templates containing, for example, different company logos and texts.
This page allows you to add, edit and delete SPX templates.
Figure 460: SPX Templates
Add SPX Templates
SPX Encryption is available in Sophos Firewall XG105 and higher models, Cyberoam CR25iNG and higher models, and all Sophos UTM Models.
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This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
This page allows you to define new SPX Templates or modify existing templates.
1. Go to Protect > Email > Encryption > SPX Templates and click Add.
2. Enter parameter values for the following basic settings.
Name
Specify the name to uniquely identify the template. The name should be a string containing alphanumeric and special characters EXCEPT forward slash (/), backslash (\), comma (,), double quote (") and single quote (').
Description
Specify details of the template.
Organization Name
Specify the organization name to be displayed on notifications concerning SPX sent to the administrator or the email sender, depending on your settings.
PDF Encryption
Select the encryption standard of the PDF file.
Page Size
Select the page size of the PDF file.
Figure 461: General Settings
3. Enter Password Settings.
Password Type
Select how you want to generate the password for accessing the encrypted email message. The sender always has to take care of transferring the password in a safe way to the recipient, unless you select Specified by recipient.
Available Options:
Specified by Sender:
If you select this, the email sender should provide the password. The sender has to enter the password into the Subject field, using the following format:
[secure:<password>]<subject text> where <password> is the password to open the encrypted PDF file and <subject text> is the random subject. Of course, the password will be removed by the Device before the email is sent to the recipient.
Generated one-time password for every email:
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The Device automatically creates a new password for each affected email. An email notification is mailed to the sender containing instructions and the one-time generated password.
The HTML content of this Email can be customized from Notification Subject and Notification
Body. You can reset to the default content by clicking Reset .
Generated and stored for recipient:
The Device automatically creates a recipient-specific password when the first email is sent to a recipient. This password will be sent to the sender. With the next email, the same password is used automatically. The password will expire when it is not used for a configured time period, and it can
be reset by the administrator, see
.
The HTML content of this Email can be customized from Notification Subject and Notification
Body. You can reset to the default content by clicking Reset .
Specified by recipient:
If you select this, the email recipient should provide the password. The recipient receives an email notification containing a link leading to the Password Registration Portal to register a password and the Sender receives a failure notification. After registration, the recipient is able to view the current encrypted mail and any future encrypted mails using the same password from this or other senders from the same organization.
Note: The Recipient's password generated via Specified by recipient method and
Generated and stored for recipient are mutually exclusive. The recipient will have to use the respective password when email is received after SPX Encryption using different methods.
Figure 462: Password Settings
4. Specify Recipient Instructions:
Instructions for Recipient
The body of the email that is sent from the Device to the email recipient containing instructions concerning the encrypted email. Simple HTML markup and hyperlinks are allowed. You can also use variables, e.g.,
%%ORGANIZATION_NAME%%
Tip: The Default SPX Template on this tab contains all available variables and gives a useful example of recipient instructions. The variables used are:
• ENVELOPE_TO: The recipient for whom the password is generated.
• PASSWORD: The password to open SPX encrypted Email
• ORGANIZATION_NAME: The name provided in the Organization Name field.
• SENDER: The sender of the email.
• REG_LINK: The link to the Registration Portal for registering the password.
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Figure 463: Recipient Instructions
General Settings
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
Email Configuration allows you to configure the general settings Email traffic. This page contains the following sections.
SMTP Deployment Mode
MTA mode is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
Click button to switch to MTA/Legacy Mode.
In MTA Mode, Device acts as a Mail Transfer Agent (MTA). In Legacy Mode, Device acts as a transparent proxy.
When acting as an MTA, Device is responsible for routing Emails to and from the protected Email Server(s). In this state Device allows you to:
• configure relay of inbound and outbound Emails from Email > Relay Settings.
• set up multiple SMTP Profiles to protect multiple Domains on your internal Email Server or multiple Email
Servers from Email > Policies > SMTP Policies.
• view email messages that are either waiting for delivery or have produced an error in the Email > Mail Spool.
• view the logs for all the emails processed by the Device from Email > Mail Logs.
Default: MTA Mode is enabled.
Note:
• On enabling MTA Mode, a firewall rule to allow SMTP/SMTPS traffic is automatically created.
• If you have migrated from CyberoamOS to SFOSv16 OR SFOSv15 to SFOSv16, Legacy Mode will be enabled by default.
Figure 464: SMTP Deployment Mode
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Banner Settings
Append Banner to All Outbound Messages
Enable to add a banner at the end of all outgoing Email messages.
The banner is appended ONLY when SMTP and SMTPS Scanning is enabled in the relevant
Business Application Policy(s).
Email Banner
Specify a banner to be added to all outgoing Emails. Only text banners are allowed.
Example:
This email contains confidential information. You are not authorized to copy the contents without the consent of the sender. Please do not print this email unless it is absolutely necessary. Spread environmental awareness.
Figure 465: Banner Settings
SMTP Settings
SMTP Hostname
Specify the SMTP hostname to be used in HELO and SMTP banner strings. By default, Device uses
'Sophos' as hostname.
Note: For Legacy Mode, this hostname is applicable only to system-generated notification emails.
Don't Scan Emails Greater Than
Specify maximum file size (in KB) for scanning. Files exceeding this size received through SMTP/S will not be scanned.
Default - 1024 KB
Specify 0 to increase the default file size scanning restriction to 51200 KB.
Action for Oversize Email
Specify the action for Oversize Emails.
Available Options
Accept: All the oversize mails are forwarded to the recipient without scanning.Reject: All the oversize mails are rejected and sender is notified.Drop: All the oversized mails are dropped, without notifying the sender.
Bypass Spam Check for SMTP/S Authenticated Connections (Available in Legacy Mode only)
Enable to bypass Spam Scanning for Email messages received over SMTP/S connections authenticated by the Email Server.
Verify Sender's IP Reputation
Click to verify the reputation of the sender IP Address. When enabled, the Device dynamically checks the sender’s IP Address of all Emails. If the IP Address is found to be responsible for
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Rules.
If enabled, specify an action for Confirmed Spam Emails and Probable Spam Emails.
Available Options
Accept: All the spam Emails are forwarded to the recipient after scanning as per the configuration.
Reject: All the spam mails are rejected and a notification is sent to the Email sender. Drop: All the spam mails are dropped, without notifying the sender.
As it is a global option, if spam scanning is enabled, all the mails will first be subjected to IP
Reputation filtering followed by filtering based on actions configured in the spam policy.
Default - Disable
SMTP DoS Settings
Enable to configure SMTP DoS Settings which protect the network from SMTP DoS Attacks.
If this is enabled, specify values for Maximum Connections, Maximum Connections/Host,
Maximum Emails/Connection, Maximum Recipients/Email, Email Rate per Minute/Host and
Connections Rate per Second/Host.
Maximum Connections (Available if SMTP DoS Settings Enabled)
Specify maximum number of connections that can be established with the Email Server.
Default - 1024
Acceptable Range - 1 - 20000
Maximum Connections/Host (Available if SMTP DoS Settings Enabled)
Specify maximum number of connections allowed to the Email Server from a particular host.
Default - 64
Acceptable Range - 1 - 10000
Maximum Emails/Connection (Available if SMTP DoS Settings Enabled)
Specify maximum number of Emails that can be sent in a single connection.
Default - 512
Acceptable Range - 1 - 1000
Maximum Recipients/Email (Available if SMTP DoS Settings Enabled)
Specify maximum number of recipientsfor a single Email.
Default - 100
Acceptable Range - 1 - 256
Email Rate per Minute/Host (Available if SMTP DoS Settings Enabled)
Specify number of Emails to be sent from a particular host in one minute.
Default - 512
Acceptable Range - 1 - 20000
Connection Rate per Second/Host (Available if SMTP DoS Settings Enabled)
Specify number of connections allowed to the Email Server from a particular host in one second.
Default - 8
Acceptable Range - 1 - 20000
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Figure 466: SMTP Settings
POP/S and IMAP/S Settings
Don't Scan Emails Greater Than
Specify maximum file size (in KB) for scanning. Files exceeding this size received through POP/
IMAP will not be scanned.
Default - 1024 KB
Specify 0 to increase the default file size restriction to 10240 KB.
Recipient Headers
Specify Header value to detect recipient for POP3/IMAP.
Default - Delivered-To, Received, X-RCPT-TO
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Figure 467: POP/S and IMAP/S Settings
SMTP TLS Configuration
TLS Certificate
Select the CA Certificate or Server Certificate for scanning SMTP traffic over SSL from the available options.
Available Options
Default ApplianceCertificate SecurityAppliance_SSL_CA List of custom CA Certificates and
Server Certificates, if added. You can create the custom CA Certificate from Certificates >
Certificate Authorities and custom Server Certificate from Certificates > Certificates.
Allow Invalid Certificate
If enabled, SMTP over SSL connections will be allowed with an invalid certificate from the Email
Server. Disable this option to reject such connections.
Default - Enable
Require TLS Negotiation with Host/Net
Select the remote host (Email Server) or network from available options on whose connections
TLS encryption is to be enforced. In other words, the Device will always initiate TLS-secured connections when Emails are to be sent to selected hosts/networks. If TLS is enforced but connection cannot be established, then Emails to that remote host/network are discarded.
Require TLS Negotiation with Sender Domain
Specify the Sender Domain(s) on whose Email connections TLS encryption is to be enforced.
Sender Domain is the domain of the Email sender. Emails from the specified Sender Domain will be sent over TLS-encrypted connections only. If TLS is enforced but connection cannot be established, then Emails from that sender domain are discarded.
Skip TLS Negotiation Hosts/Nets
Select the remote host (Email Server) or network from available options on whose connections TLS encryption is to be skipped or bypassed. When configured, SMTP connections to selected hosts will be established in clear text and unencrypted.
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Figure 468: SMTP TLS Configuration
POP and IMAP TLS Configuration
TLS Certificate
Select the CA for scanning POP and IMAP traffic over SSL from the available options.
Available Options
DefaultSecurityAppliance_SSL_CAList of custom CAs if added. You can create the custom CA from Certificates > Certificate Authorities.
Allow Invalid Certificate
If enabled, POP and IMAP over SSL connections will be allowed with invalid certificate from the
Mail Server. Disable to reject such connections.
Default - Enable
Figure 469: POP and IMAP TLS Configuration
Email Journaling (Available in Legacy Mode only)
Email being one of the most important communication and business tools in use by organizations, email journaling has become an integral part of every organization.
Using the Device's Email Journaling, the administrator can store all incoming Emails, or Emails for a specific recipient or a group of recipients and thereby keep a close watch over data leakage.
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The device can journal all Emails intended for single or multiple recipients and can forward them to a single administrator or multiple administrators.
This section displays a list of the archivers created and provides options to
,
update the parameters of existing archiver
, or delete the archiver. You can filter the list based on recipient name.
Figure 470: Email Journaling
Spam Check Exceptions
To bypass spam scanning of certain domains, define the domains as Spam Check Exceptions. The page lists all the domains configured to be exempted from spam scanning.
It also provides the options to add a new domain and delete an existing domain.
Figure 471: Spam Check Exceptions
Malware Protection
Malware Protection is available in Sophos Firewall XG105, Cyberoam CR500iNG, Sophos UTM SG105, and higher models.
Sophos Firewall offers dual anti-virus scanning, wherein traffic is scanned by two (2) anti-virus engines. Traffic is first scanned by the primary engine, and then by the secondary engine.
Primary Anti Virus Engine
Select the primary anti-virus engine for traffic scanning. For dual scan, packets are first scanned by the primary engine and then by the secondary engine. For single scan, only the primary engine is used.
Available OptionsSophosAvira
Note: Selecting Avira will disable Sandstorm in all SMTP Policies with Single Anti-Virus Scanning.
Figure 472: Malware Protection
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Advanced SMTP Settings (Available in MTA Mode only)
Reject invalid HELO or missing RDNS
Select this option if you want to reject hosts that send invalid HELO/EHLO arguments or lack
RDNS entries. Select Do strict RDNS checks if you want to additionally reject email from hosts with invalid RDNS records. An RDNS record is invalid if the found hostname does not resolve back to the original IP address.
Scan Outgoing Mails
Enable to scan all outgoing email traffic. Email is quarantined if found to be malware infected, or marked as Spam.
Figure 473: Advanced SMTP Settings
Add Email Journal
Email Journal appears only when Legacy mode is enabled. The device acts as a transparent proxy.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The Add Email Journal page allows you to specify which recipient's Email you want to store.
1. Go to Email > General Settings and click Add under Email Journaling.
2. Enter the following parameters.
Name
Enter a name for the Email Journal.
Recipient
Select Any to journal all the incoming Emails or specify the Address Group for which Emails need to be stored.
Send Copy of Email To (Only for SMTP/S Protocol)
Specify the Email Address to which you want to forward the Email copy.
Figure 474: Email Archiver
3. Click Save.
Address Groups
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Policies are applied on Email Addresses. To make configuration easier and simpler, the Administrator can group the addresses that require the same scanning policy. The policy applied to the address group is applicable to all the group members. Hence when the group is used in a number of rules, it becomes much easier to add or remove addresses from the group rather than updating individual rules. Hence, just with the one update, the Administrator can re-align the rules.
An Address Group is a grouping by:
• Email Address or Domain
• IP Address
• RBL (Real time black hole List) (applicable only for the spam email)
An address can be a member of multiple groups.
An RBL is a list of IP Addresses whose owners are responsible for spam or are hijacked for a spam relay. These IP
Addresses might also be used for spreading viruses. The Device checks each RBL for the connecting IP Address and the action configured in the policy is taken if the IP Address is found in any of the RBL lists. The Administrator can directly use the two default RBL groups shipped with the Device or update them as per their requirement:
• Premium RBL Services
• Standard RBL Services
The Address Group page displays a list of all the default and custom groups and provides options to add a new group, update the parameters, import addresses in the existing group, or delete the group. You can sort the list based on address group name.
Add Address Group
1. Go to Protect > Email > Address Group and click Add.
2. Enter a name and description.
3. Group Type: Select to add email addresses or domains to the address group.
Available Options:
RBL (IPv4) or RBL(IPv6):
Select to add RBLs of IPv4 or IPv6 addresses or domain names.
If the connecting IP address is found on the RBL, the device takes the action specified by the relevant policy.
Email Address/Domain:
Select to add the email address or domain name.
Import: Select to upload a CSV or text file.
Manual: Select to add individual email addresses or domains.
Note:
• You can import a maximum of 400 email addresses or domains in a single file.
• Invalid and duplicate entries are not imported.
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Figure 475: Address Group
4. Click Save.
File Types
A file type is a classification that is determined by file extension and MIME header. You can include file types in web policies to control access to files that match the specified criteria. The default file types contain some common criteria and you can create additional types.
Using File Types with Policy Rules
You can create file types to control access to files on a more granular level. For example, you may want to allow access to SQL files but deny access to all other database files. In this case, you would create a file type for SQL files and a policy that specifies the following rules in the following order:
1. Allow access to SQL files
2. Block access to all database files
Add File Type
1. Go to Protect > Web > File Type and click Add.
2. Type a name.
3. (Optional) Select a template.
You can select from predefined or custom file types. If you do not wish to use a template, choose Blank.
4. Specify the file extension and MIME header.
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Figure 476: Add File Type
Quarantine Digest
Quarantine Digest is available only in Sophos Firewall XG105, Cyberoam CR25iNG, Sophos UTM SG105, and higher models.
This feature requires a subscription. It can be configured but cannot be enforced without a valid Email
Protection subscription.
The Quarantine Digest is an Email containing a list of quarantined Emails filtered by the Device and held in the user
Quarantine Area. If it is configured, the user receives a Quarantine Digest as per the frequency defined on this page.
The digest also provides a link to the User Portal from where the user can access quarantined Emails and take the required action.
The Quarantine Digest settings can be configured globally for all the users or for individual users. The user receives the Quarantine Digest as per the configured frequency.
The Quarantine Digest provides the following information for each quarantined message:
• Date and time: Date and time when the message was received
• Sender: Email address of the sender
• Recipient: Email address of the receiver
• Subject: Subject of the message
Configuring the Quarantine Digest for All Users
Enable Quarantine Digest
Enable the Quarantine Digest to configure the digest service for all the users.
Email Frequency
Specify the mailing frequency for digest.
Digests can be mailed every hour, every day at configured time, or every week on the configured day and time.
From Email Address
Specify the Email Address from which the email should be sent.
Display Name
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