I am having an odd issue. One of my users cannot recieve mail from a specific external domain. He is working with two different contacts at this domain. Both contacts can send mail to me, but when they send mail directly to this user or send to me and CC this user in my domain I will get the messages, but the user will not. In Message Tracking I can see the messages come in, but only to me, I do not see the message come in for the other user - even though when I open the message in Outlook I can see the user is in the "To" or "CC" line. The people at the other domain get an NDR that the message to this user expired. #550 4.4.7 QUEUE.Expired; message expired ## Is there somewhere I can start looking to resolve this on my end, or is this problem most likely on the senders end. I am runing Exchange 2003. Thank you, for any suggestions/guidance

Hi, You can enable SMTP logging on your server. When this is enabled ask the other company to send mail to the user in question and see if you can see anything in the log. If you don't see anything the problem must be at the other side (even if it is hard to see what that might be) http://support.microsoft.com/kb/265139 Leif

So the issue is : a special external domain can't send email to a mailcontact in your organization. Am i correct? If so, i think you can't do anything to resolve the issue. Are you able to send email to the mail contact? Also try to send email from other external email address, such as @hotmail.com to the mailcontact, can the mail contact receive email? When the special domail send email to the mail contact, the email will not route into your organization. So you can't get any log on your Exchange server.