We use our Barracuda Spam Firewall to encrypt outgoing emails based on a recipient filter list. After migrating from GroupWise to Exchange 2013 we have run into an issue. An employee sets up an automatic reply in Outlook and is then emailed by someone on the encryption list. Exchange replies to the email with the automatic reply but gives the mail no sender. The barracuda calls foul on this and says the domain is not verified for encryption and will not send out the mail. Anyone have a clue about fixing this?
From what I have read Exchange sends the mail with no sender by design.
The blank sender is causing the Barracuda to think the sending domain is 127.0.0.1, an impossible to verify domain.