6. AVG for Kerio MailServer
6.1. Configuration
The anti-virus protection mechanism is integrated directly into the Kerio MailServer application. In order to activate e-mail protection of Kerio MailServer by the AVG scanning engine, launch the Kerio Administration Console application. In the control tree on the left side of the application window choose the Content Filter sub-branch in the Configuration branch:
Clicking the Content Filter item will display a dialog with three items:
· Spam Filter
·
·
Antivirus
(see section Antivirus)
Attachment Filter
(see section Attachment Filter)
6.1.1. Antivirus
To activate AVG for Kerio MailServer, select the Use external antivirus checkbox and choose the AVG Email Server Edition item from the external software menu in the
Antivirus usage frame of the configuration window:
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In the following section you can specify what to do with an infected or filtered message:
· If a virus is found in a message
·
This frame specifies the action to be carried out when a virus is detected in a message, or when a message is filtered by an attachment filter: o Discard the message – when selected, the infected or filtered message will be deleted.
o o
Deliver the message with the malicious code removed – when selected, the message will be delivered to the recipient, but without the possibly harmful attachment.
Forward the original message to administrator address – when selected, the virus infected message is forwarded to the address specified in the address text field o Forward the filtered message to administrator address - when selected, the filtered message is forwarded to the address specified in the address text field
If a part of message cannot be scanned (e.g. encrypted or corrupted file)
This frame specifies the action to be taken when part of the message or attachment cannot be scanned: o Deliver the original message with a prepared warning — the message
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o
(or attachment) will be delivered unchecked. The user will be warned that the message may still contain viruses.
Reject the message as if it was virus — the system will react the same way as when a virus was detected (i.e. the message will be delivered without any attachment or rejected). This option is safe, but sending password protected archives will be virtually impossible.
6.1.2. Attachment Filter
In the Attachment Filter menu there is a list of various attachment definitions:
You can enable/disable filtering of mail attachments by selecting the Enable attachment filter checkbox. Optionally you can change the following settings:
· Send a warning to sender that the attachment was not delivered
·
The sender will receive a warning from Kerio MailServer, that he/she has sent a message with a virus or blocked attachment.
Forward the original message to administrator address
·
The message will be forwarded (as it is — with the infected or forbidden attachment) to a defined email address, regardless of whether it is a local or an external address.
Forward the filtered message to administrator address
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The message without its infected or prohibited attachment will be (apart from the actions selected below) forwarded to the specified e-mail address. This can be used to verify the correct functioning of the antivirus and/or attachment filter.
In the list of extensions, each item has four fields:
·
·
Type – specification of the kind of attachment determined by the extension given in the Content field. Possible types are File name or MIME type. You can select the respective box in this field to include/exclude the item from attachment filtering.
Content – an extension to be filtered can be specified here. You can use operation system wildcards here (for example the string ‘*.doc.*’ stands for any file with the .doc extension, and any other extension following).
· Action – define action to be performed with the particular attachment. Possible actions are Accept (accept the attachment), and Block (an action will be performed as defined above the list of disabled attachments).
Description – description of the attachment is defined in this field.
·
An item is removed from the list by pressing the Remove button. You can add another item to the list by pressing the Add… button. Or, you can edit an existing record by pressing the Edit… button. The following window then appears:
·
·
In the Description field you can write a short description of the attachment to be filtered.
In the If a mail message contains an attachment where field you can select the type of attachment (File name or MIME type). You can also choose a particular extension from the offered extensions list, or you can type the extension wildcard directly.
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In the Then field you can decide whether to block the defined attachment or accept it.
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