Exchange 2003 SP2, running on Windows 2003 SP2 in Windows 2003 domain (all Exchange servers and all users+mailboxes in one domain in a two-domain forest).
For the past week or so, we've had two major Categorizer problems, randomly on almost all 30 of our Exchange servers: 1) Messages Awaiting Directory Lookup (PreCatQueue) will start to fill up...no particular action we've taken will resolve this. It seems to start working again randomly (maybe when the Categorizer starts talking to a different DC?) 2) Random messages, both internal an external recipients affected, will NDR with a 5.1.0 error. With diagnostic logging turned up to full, we see the following events when the problem is going on: EventID 6010 - Categorizer is temporarily unable to process a message. The function 'CCfgConnection::AsyncSearch' called 'CBatchLdapConnection::AsyncSearch' which returned error code '0xc004051f' (). ( f:\tisp2\transmt\src\phatq\cat\ldapstor\cnfgmgr....@2353 ) EventID 8260 - Could not open LDAP session to directory 'DC1.domain.local' using local service credentials. Cannot access Address List configuration information. Make sure the server 'DC1.domain.local' is running. Does anyone have any ideas? We have a case open with Microsoft there, but they seem to be scratching their heads as well... We've tried reboots of Exchange servers and DCs, unhooking VSAPI and antivirus scanners on the Exchange side, and DCDIAG from the Exchange server to the DCs, and locally on the DCs are clean. Thanks in advance, if anyone has thoughts... --James
