Using Attachment True File Type Criteria

The Attachment is "true file type" criteria allows you to create rules that take actions on messages based on the true file type of attachments a message contains.

Note:

Where the Attachment is "name or extension" criteria makes decisions based on just filenames and/or extensions, the Attachment is "true file type" criteria scans the headers of the files themselves for the identifying signatures.

On the Criteria screen, select Advanced to display the advanced criteria.
Select the Attachment is "true file type" criteria.
Click the "true file type" link.
The Attachment True File Type screen appears.
From the drop-down list, select Selected attachment types or Not the selected attachment types.
Select the true file types for Hosted Email Security to match on.
Note:
The Compressed file type of other includes only the following file types: ar, arc, amg, lzw, cab, lha, pklite, diet, lzh, and lz.