Attached files filtering feature can be used if trough the Policies service. It allows creating rules according extensions in attached files and files inside ZIP files.
- On the Policies service, turn on the Attached files filtering option.
- On the Messaging section, click on the Attached Files filtering
- On the Main table, create a new rule.
- set the sender and recipient that will matches the rule.
- Click on the Added rule and select the Extensions tab.
- You will see some extensions added by default.
- You can remove and add extensions for this rule.
- Click on template tab in order to personalize the content of the replaced file that matches the rule.