I manage an Exchange 2003 server with all service packs and security fixes applied. I have triple checked this server so that it does not relay. I even used the following article to confirm its setup not to relay:
Everything checks out. However, when I run an online relay test on http://www.test-smtp.com/
its states my server is a relay. This site conducts 28 tests, and on Test 17 it states Host is an open relay!
I ran another online test on this site: http://www.antispam-ufrj.pads.ufrj.br/test-relay.html
and it stated "Relay test result
Ops!!! Host appeared to accept a message relay, but it may or not may a positive open relay. I need procced a complete test, sending a test message to probe it. This anonymous user test did not send a test message. "
I manage several Exchange 2003 servers with an identical smpt connector setup and do not have a relay problem.
In the app event viewer, I saw the following Event ID 7010 (MSExchangeTransport) message:
Event Type: Error
Event Source: MSExchangeTransport
Event Category: SMTP Protocol
Event ID: 7010
Time: 3:20:21 PM
This is an SMTP protocol log for virtual server ID 2, connection #8. The client at "18.104.22.168" sent a "rcpt" command, and the SMTP server responded with "550 5.7.1 Unable to relay for relaytest%antispam-ufrj.pa
2.59] ". The full command sent was "rcpt TO:<relaytest%antispam-ufr
". This will probably cause the connection to fail.
I am a bit confused in that this server could a relay, but I've done everything possible to ensure its not. Any ideas as to what is going on?