I have a SBS 2003 server at the main office with about 15 users. Last week, I setup Exchange 2003 Standard on a Windows Server 2003 R2 (SP2) server at a branch office (all one AD domain and one Exch Org) so that the 3 users at the branch office could have local email boxes. Exchange on the SBS 2003 server and the branch office server have SP2 for Exch 03 installed. I was able to move one mailbox over the WAN (a VPN), but 2 users had mailboxes that were too big. So I backed up the 2 mailboxes to PST, deleted the mailboxes on the SBS server, created new mailboxes on the new Exchange server at the branch office, and restored the PST's.All email from the branch office is flowing to the main office, but some mail is queuing up from the main office to the branch office. I know some mail has gotten through. I tried restarting all the Exchange services at both offices. I tried deleting all the messages from the queue at the main office.There were no errors in the event logs at the branch office. I did find an event log error on the main office server (SBS03):Event Type: ErrorEvent Source: Server ActiveSyncEvent Category:NoneEvent ID: 3005Which from "http://eventid.net/display.asp?eventid=3005&eventno=2656&source=Server ActiveSync&phase=1" (you may need an account to see that page), I went to Exchange System Manager - Servers - <server> - Protocols - HTTP - Exchange Virtual Server, deleted "Microsoft-Server-ActiveSync" and then recreated it. Now I am not getting that error.I rebooted the branch office server and the queued up messages on the main office server went. But now they are queuing up again, but leaving the queue very slowly. Mail flow from the branch to the main office is fast and fine...has never had a problem.Any ideas?

Update:Some mail is flowing, but some mail is not. I just rebooted both servers. There are 4 msgs in the queue from the main office to the branch office...2 are from a mailbox on the main office server to a mailbox on the branch office server...2 are system msgs. The oldest in the queue "Time received by server" is 4:01 PM and the newest in the queue "Time received by server" is 6:51 PM...the current time is 9:31 PM.

This morning the issue became critical (email stopped altogether). So I called Microsoft PSS and initiated a critical case/ticket. But before PSS could call back, our network engineer fixed the issue and now mail is flowing normally.The issue was the firewall at the branch office. It had rules that were restricting mail flow. I had worked with the network engineer yesterday to try and resolve this issue, but he didn't want to change anything. This morning, he removed all restrictions; since this is an internal connection, this is the way it should be anyway. The connection to the internet for the company is still firewalled.