I setup an Exchange 2013 server with the roles all on the same server. The domain administrator's password expired and when i changed it the relay connector stopped working. I'm allowing an Solaris server to relay emails for some developers. When I created a new connector it began to work again. Would changing the password have any effect on receive connectors? Or was this just a coincidence?
Here are the instructions that I followed to create the relay. http://glazenbakje.wordpress.com/2012/12/30/exchange-2013-how-to-configure-an-internal-relay-connector/