The problem:
SMS for SMTP 5.0.1 patch 189 running on Windows Server 2003 Standard SP1 (we were toldby Symantec that SMS for SMTP 5.0.1 is not support on SP2) is timing out waiting for response from our mailservers upstream.
The layout:
MailGateways (2 servers) -----> SMSSMTP servers(2) ----> InternalPOPservers(2) -----> Exchange 2003(2)
Setup info:
The mail gateways and internal pop servers are W2K3 Standard SP2 running regular IIS SMTP
Exchange is W2K3 Enterprise SP2
The mail gateways are running 1 SMTP mail routing sink (which is why SMSSMTP isn't currently the mail gateway)
The MX record that is being used by the mail gateway is
smssmtp server1 - cost 0
smssmtp server2 - cost 0
internalpop1 - cost 5
internalpop2 - cost 5
More detail:
We see in the SMTP log files of both mail gateways, 451 timeout messages coming from both SMSSMTP servers. After the timeout is received the mail gateways connect to the internal pop servers and dump messages, bypassing the SMSSMTP servers so now we have spam and viruses leaking through. Has anyone had this problem?
Additional info:
We had one SMSSMTP server at patch level 189 and another with no patches at all. The SMSSMTP server WITHOUT any patches had no timeouts and when we had this configuration of no mail was bypassing the SMSSMTP servers. We noticed that the unpatched server allowed use of the BDAT command and the patched version did not. We still saw timeouts being generated by the patched SMSSMTP server but again, no messages bypassed the SMSSMTP servers. Now that both servers are patched, both are timing out and for a reason uknown to me the the mail gateways.
What could be causing the timeouts? The mail gateways are sending the <crlf>.<crlf> to indicate the end of messages but often the SMSSMTP server just don't see it. And when the SMSSMTP servers are unpatched it looks like it relies on the BDAT command to determin the length of the messages and everything is all good. HELP!