I have a domain with about 200 users on Zimbra 7.2. I'd like for everyone to be able to receive mp3 files except ONE user. I want that one user to just reject emails with an attachment whose name ends with .mp3. I want that one user to be able to receive other attachment types, just not mp3.

I have found methods for rejecting attachment types globally for all users, but I'm looking to reject just one attachment type for just one user.

The message filters at the account level don't seem to be able to work with attachments other than determining if it "exists" or "does not exist."

Any suggestions would be greatly appreciated!