Default Blocked File Attachments
To view what file attachments are being blocked by Zimbra mail, you can do the following.
Step 1. Login to the Control Panel and under 'Your Customers' click on the customer's account you wish to manage.
Step 2. From the customer's account page, click on the Product Name you wish to manage - in this example it's Zimbra Email.
Step 3. Under 'Product Configuration' click on Virus & Content Handling
You should now be able to see the default virus and content handling settings, and also which email attachments are blocked: