Attachment Blocking

Use the Attachment Blocking page to specify types of attachments to block from incoming and outgoing email messages and actions to take on blocked messages. Attachments are blocked based on message MIME types and filename types. In addition to selecting the types of message attachments to block, you can define actions to take on blocked messages.

An attachment blocking folder exists for each email domain and the attachment blocking options can be based on the current email domain or the primary email domain settings.

Use the Users Attachment Blocking page to search for attachment blocking types in the selected domain, access and edit attachment blocking types, add new attachment blocking types, or delete attachment blocking types.

Search box. Enter an attachment blocking type that you want to search for in the current domain attachment blocking type list, then click Search.
Clear. Click Clear to reset the attachment blocking type search results list to display all available attachment blocking types in the current domain.
Content list. Click an attachment blocking type to modify the properties.
Add. Click Add to create a new attachment blocking type for the current domain. For more information, see Adding Attachment Blocking Rules.
Delete. Select an attachment blocking type that you want to delete from the current domain, then click Delete to delete the type.

Attachment Blocking Message

The message box includes a default message that provides information about the attachment that has been removed. You can also create a custom message that replaces attachment body content that has been blocked.

When an attachment is blocked and the Replace Attachment option is selected in the Action for match list (on the Add Blocker page accessed by clicking Add on the Attachment Blocking page), a custom message is sent in the place of the attachment to the message recipient.

Use:

Current Domain. Select this option to define attachment blocking messages specific to the current email domain.
Primary Domain (default). Select this option to define attachment blocking messages based on the primary email domain's message settings.

This message will replace the body of a blocked email attachment:

Use the default message that is included in the message box or enter a custom message to send email recipients when an attachment is blocked. You can include variables in the custom message:

%t to indicate the message type (MIME or filename)
%c to indicate the filename of the blocked attachment (if applicable)

The contents of the message box are saved in a file named ab-message.txt located in the appropriate email domain's top directory. The message box text should only be edited from the Attachment Blocking Message tab and is limited to 924 characters.

Note: If you want to log messages from the attachment blocking feature, make sure that the Verbose Logging is selected on the SMTP Settings Page.