Our Ex2k3 server seems to terminate it's LDAP session with the DCs periodically and cause the MAPI flow timeout. Here's the event that seemed to correspond with the last MAPI flow error. Event 2389 Process STORE.EXE (PID=4260). A search request to Directory Server server.domain.net did not return a result within 30 seconds and is being abandoned. The search will be retried if possible. The search that failed has the following characteristics: Base DN=<GUID=91C48E7D-4FF1-4634-925A-20D4D9D32650>, Filter=(objectclass=*), Scope=5b1efcc8. Can't find anything concrete on this. However, I'm looking at this article about win2k3sp1 or security update ms05-019 causing network isssues including "Inability of Microsoft Exchange servers to connect to domain controllers." If this is the case, I would imagine many others experiencing this. Has anybody experienced any dsaccess issues because of sp1 or this security update or have any insight on this event id? Thanks. http://support.microsoft.com/?id=898060 <http://support.microsoft.com/?id=898060>