All incoming email is blocked on Barracuda. I tried to use a gmail email to send to a email address on Exchange server. The following message is returned,
"Delivery to the following recipient failed permanently:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain abc.com by mailgate.abc.com. [xx.xx.xx.xx].
The error that the other server returned was:
550 No such domain at this location