About attachment lists
An attachment list contains the file extensions and the file application types that you want Symantec Messaging Gateway to detect. When Symantec Messaging Gateway detects an attachment that has an extension that is on the file extension list, it applies the action that you specify. Symantec Messaging Gateway can determine the email attachment type based on the application that created it, regardless of its file extension.
You can create an attachment list with any combination of the following:
True file classes | True file classes are categories in which similar file types and applications are grouped. For example, Desktop publishing and Movie file are true file classes. Within a true file class are the true file types. For example, FrameMaker is a true file type within the Desktop publishing true file class. You cannot modify the list of true file types within a true file class. You must use the list as is. |
True file types | True file types are contained within a true file class. True file types consist of file extensions or applications. For example, a true file type within the category Desktop publishing is FrameMaker. A true file type within the category Movie file is MPEG movie. You can add and delete items in a true file types list. The Archive Files attachment list does not support true file type MIME. The Document Files attachment list does not support true file type HTML. |
Common file extensions and MIME-types | You can specify common file extensions and MIME-types. For example, you can filter out all .jpeg file attachments, regardless of the application that created it. For a technical description of MIME, see the following RFC: |
Symantec Messaging Gateway provides default attachment lists. You cannot modify default attachment lists; however, you can copy them and modify the copies as needed. Or you can create your own custom attachment lists.