Some user's on another domain (.gov domain) are getting these replies back when trying to e-mail some users on our own domain (non-government domain).
The messages will read like this to them:
The message or an attachment did not reach the intended recipient(s).!
Date: Wed, 22 May 2013 02:19:33 -0600
Reason: domain.gov must use TLS
Is this usually something can be fixed on the exchange end of our domain or something going on with the government domain email server?