I have an exchange server that is acting up and i'm a little stuck. First some info.
This is a SBS2k3 fully updated, running Exchange 2k3 also fully updated. This install is fresh as of about a month ago. It also has the GFI mailsecurity and essentials, As well as AVG's email edition, however i have that disabled currently.
Whats happeneing is some of the mail is getting stuck up in the Q, and won't leave. When u highlight one of the Q's, box below "Additional Queue Information" says that "The connection was dropped by the remote host"
I switched on SMTP logging to get a little more info and at first i was getting 7004 events.
This is an SMTP protocol error log for virtual server ID 1, connection #272. The remote host "xxx.xxx.xxx.xxx", responded to the SMTP command "xexch50" with "504 Need to authenticate first ". The full command sent was "XEXCH50 2556 2 ". This will probably cause the connection to fail.
After a little research i found the Xexch supress reg key and added that in. Now i havn't seen a 7004 for a while, but i am now getting 7002 events.
This is an SMTP protocol warning log for virtual server ID 1, connection #5. The remote host "xxx.xxx.xxx.xxx", responded to the SMTP command "rcpt" with "451 Can't connect to kocolene.com - psmtp ". The full command sent was "RCPT TO:<firstname.lastname@example.org> ". This may cause the connection to fail.
Right now i'm only seeing the 7002 error for that 1 domain. However i have emails for 2 other domains just sitting there retrying, then failing and giving the standard 'The connection was dropped by the remote host" But they are not showing up in the event viewer. I have also tried switching from the EHLO command to the older HELO command, however that didn't appear to make any difference what so ever.
We have been able to send email to these domains before, And sometimes mail goes right though. For instance i got all the notifications i should have when i rebooted the server this morning, however another email to the same domain a while later seems to now be stuck. It seems as though it works for a short time after a reboot then goes to hell after that.