We are troubleshooting a problem on what should be a simple SBS 2003 server setup.
All mail is delivered via an SMTP connector and all mail is received by POP connectors. The SMTP connector works perfectly but the POP connectors are having problems.
Mail is being retreived from the external server. Following KB885685, we traced the incoming mail and can see it arrive in the Incoming Mail folder and transfer to the Pickup Folder but from there, it goes nowhere. With message tracking turned on, we see the following:
SMTP: Message Submitted to Advanced Queuing
SMTP: Started Message Submission to Advanced Queue
SMTP: Message Submitted to Categorizer
I've Googled the problem but everything Microsoft has to say about messges stuck in the Categorizer doesn't match the symptoms. For example, KB952841: IIS doesn't have the metabase entries that cause this problem.
Other solutions simply say to run the Internet and E-mail Setup Wizard and enter the external domain name when prompted. The problem with this approach is that the domain name ends up in the default SMTP virtual server and becomes the SMTP domain in the IIS metabase; which in turn means that an internal user can't send mail to a mailbox on the external server. (Not all of the mail accounts on external mail domain have ADS user accounts on the Exchange server. Some of users are remote who access mail directly from the external mail server.)
Hopefully the above makes sense. Any help would be appreciated.