I am hoping someone can help me. I am running Exchange 2007 SP1 on a Windows 2008 Sp1 server. I am not able to send or receive emails externally, internally works fine. Looking over some of the similar cases non seem to resolve my problem. looking in the queue viewer I am seeing the following message:
451 4.4.0 Primary Target IP address responded 421 4.2.1 unable to connect.
I have, as a test removed my anti-virus software. i also made sure that RRAS was disabled as well as the Windows firewall. Addtionally i called my ISP, Comcast, and verified that they are not blocking port 25. When i do a netstat -a i do not see port 25.
Looking at the protocol logs i am seeing this error:
2009-05-17T21:56:24.536Z,Internet - SMTP,08CBA500777A7783,1,,220.127.116.11:25,*,,"Failed to connect. Error Code: 10060, Error Message: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 18.104.22.168:25