Types of attachment filters
- Extension Filters
Using a mail's MIME headers, the attachment filter can extract a file attachment's extension, and apply a filter decision based on the listed extensions. This will not recognize a file correctly if the filename has been modified. For example, if an executable file has been renamed photo.jpg, a .exe extension filter will not detect it. In this situation, would be necessary to also use the File Type Filters and/or MIME Type filters.
File Name Filters
Using a mail's MIME headers, the attachment filter can extract a file attachment's filename, and apply a filter decision based on the listed filenames. Use an asterisk (*) to match zero or more characters and use a question mark (?) to match a single character. For example, to filter all executable attachments that include the word sample, create a filter *sample*.exe.
Mime Type Filters
Mime Type is the file type that is reported in the MIME Content-Disposition and Content-Type headers. Both are recorded in their raw (encoded) form and rfc2047-decoded form, if applicable. It consists of a general type and a specific type indicator. For example image/png, video/avi or text/html.
File Type Filters
SpamTitan Gateway scans each attachment to determine its file type. If an attachment's file type matches any of those listed in the File Type Filters table, the message will be filtered according to the particular filter settings.
How to configure the filters?
- Login to SpamTitan console using the admin role.
- Go to Content Filtering -> Attachments.
- Click Enable opposite Attachment Filtering: to enable attachment filtering.
- To add a new attachment filter, click Add... under the table for the filter type you want to add and the Add Filter dialogue box displays.
- Click Save to save this filter.
- Click Apply at the bottom of the Attachments page to commit any configuration changes you make.