Internal email gets queued

[mrbusy]

I have two Exchange servers. One is my primary server, which has recently been completely rebuilt due to an OS problem, and a temporary server. For the rebuild I moved all my users (about 25 of them) onto the temp server and changed incomnig email to the new server. I followed all the MS instrcutions on removing the first server in a site and then rebuilt the primary server. No problems at all, nothing stopped working. I have now rebuilt the primary server and everything seemed fine until I started to move users back. The first mailbox I tried was my own. I was able to send email but not receive it. I noticed that the email was being queued on the temporary server (which still gets all the inbound Internet email). I couldn't understand why the primary server would not accept delivery so I added the temporary server to the "allowed to relay" list and after a few minutes it came to life. I then tried sending internal emails and got the same problem in the other direction. While I can now use my mailbox on the primary server to send and receive externally, and also receive internally from users still on the temporary server, I cannot send replies. Messages end up queud in Remote Delivery, and go nowhere. I tried the same remedy of adding the primary server to the relay list on the temp server, but with no effect.

Can anyone tell me what's happening here and the best way to resolve it. I have the option of just moving everyone at the same time to get around it, but I would rather do a few mailboxes at a time.

Cheers.