Using Attachment MIME Content-type Criteria

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

Note:

Where the Attachment is "MIME content-type" criteria makes decisions based on the MIME content-type indicated, the Attachment is "true file type" criteria scans the headers of the actual attached files themselves for the identifying signatures.

On the Scanning Criteria tab, select Advanced to display the advanced criteria.
Select the Attachment is "MIME content-type" criteria.
Click the "MIME content-type" link.
The Attachment MIME Type screen appears.
From the drop-down list, select Selected attachment types or Not the selected attachment types.
Select the MIME types for Hosted Email Security to match on.
If you want to block attachments by explicit MIME content-types, type the names of the MIME content-types to block, under the Other MIME content-type text field.
Tip:
The following examples are valid:
- 3dm or *.3dm
- 3dmf or *.3dmf