I have a problem with sending messages from one SBS running Exchange Server 2003, Ill call it server B, to a second one Ill call server A.
I can send any email from server A to server B.
I can send email from server B to server A if it is just a small text message, most of the time and it may be delayed. Messages with attachments get stuck in the Queue.
I can send email to and from server B with other domains such as hotmail with out issues.
I can send email to and from other domains with server A without issues.
I administrate both servers.
I have run SMTPDIAG on both servers, testing the other with no problem detected.
I have built a bare server to replace server A as a test with no change. Due to the circumstances I can not do the same for the other server.
Any ideas will be greatly appreciated.