We recently upgraded to exchange 2013 and we have an issue with some emails. The issue has to do with people responding to a contactus form on our website. The website is sending the message using @domain.com in the reply address. This is the same @domain.com we use internally. I believe there is a filter someone blocking external emails that have the same domain.com as internal emails. The message the web server is getting is: 47615: failure: This_address_no_longer_accepts_mail.
Anyone know where this filter might be?