Greetings. We have in place a Barracuda 400. A few months ago, emails with attachments larger than 1 or 2mb, from just two domains, are refused and eventually returned to the sender. If either of these domains send an email with no attachment, or smaller attachments, the message will be delivered. There is nothing in the logs on the Barracuda to indicate a problem. The message is not Blocked or Quarantined. Both the sender and I have tried to figure out the problem and have come up with nothing. My last resort is to try and monitor the connection from the logs on our Firewall, which I'll be trying soon. In the meantime, has anyone come across this before?