Strange issue, and I really don't know what else to do. I am running Exchange 2003 and Exchange 2010 coexist environment. I am about half way through the transition process, but my Exchange 2003 server still receives our email. I wanted to point that out, although this problem has occured in the past long before 2010 was deployed. It seems that all email flows in to our organization just fine, except a few domains here or there. They send a message, it leaves their comapny, but never hits a users inbox here. I ahve enabled tracking, and nothing shows up. However, in the SMTP log I can see some communication between our mailserver and the domain that can not get through. Here is the snippet: 20:07:37 69.37.246.2 - - 0 20:07:37 69.37.246.2 EHLO - 0 20:07:37 69.37.246.2 - - 0 20:07:37 69.37.246.2 HELO - 0 20:07:37 69.37.246.2 - - 0 20:07:37 69.37.246.2 MAIL - 0 20:07:37 69.37.246.2 - - 0 20:07:37 69.37.246.2 RCPT - 0 20:07:37 69.37.246.2 - - 0 20:07:37 69.37.246.2 DATA - 0 20:07:37 69.37.246.2 - - 0 All 0's, what does that mean? I've done MX checks on our mail server and everything looks good. What can I do? Any advice?

On Mon, 29 Mar 2010 20:37:47 +0000, Jonathan4465 wrote:>>>Strange issue, and I really don't know what else to do. >> >>I am running Exchange 2003 and Exchange 2010 coexist environment. I am about half way through the transition process, but my Exchange 2003 server still receives our email. I wanted to point that out, although this problem has occured in the past long before 2010 was deployed. >> >>It seems that all email flows in to our organization just fine, except a few domains here or there. They send a message, it leaves their comapny, but never hits a users inbox here. I ahve enabled tracking, and nothing shows up. However, in the SMTP log I can see some communication between our mailserver and the domain that can not get through. Here is the snippet: >20:07:37 69.37.246.2 EHLO - 0 >20:07:37 69.37.246.2 - - 0 [ snip ]>All 0's, what does that mean? I've done MX checks on our mail server and everything looks good. What can I do? Any advice?I'd change the parameters on that log file so you're capturing someinformation that's meaningful. If in doubt, check ALL the boxes andcollect data for all possible data. There's not enough informationthere to know much more than the IP address of one of the MTAs andthat it said "HELO". There's no MAIL FROM command so I think it's safeto assume that the message never leaves the sending server.---Rich MatheisenMCSE+I, Exchange MVP--- Rich Matheisen MCSE+I, Exchange MVP

Hi, Please try to use telnet to simulate the sender which from the problematic domain. What's the result? Thanks Allen