I have researched this for weeks now, and have not been able to find a fix:
Our Exchange 2007 server reports a long series of Errors in the App Log, a few times each day. These errors are reported for approximately 10 minutes, and then everything is fine again. During the time that these are reported, end-users are not able to access email either through Outlook or OWA. The errors on the server's App Log vary, but always include the following types:
MSExchange System Attendant Mailbox
MSExchange RPC Over HTTP Autoconfig
Some of the first errors that are reported are that all Domain Controllers and all Global Catalog servers are not responding. However, during this time, our network is functioning just fine. Aside from mail access being down, we are able to access all Domain Controllers and Global Catalog servers just fine.
DCDiag on the Exchange server reports the following:
LDAP search failed with error 58,
The specified server cannot perform the requested operation..
The host <SERVER> could not be resolved to an
IP address. Check the DNS server, DHCP, server name, etc
NetDiag reports these errors:
Redir and Browser test . . . . . . : Failed
List of transports currently bound to the Redir
The redir is bound to 1 NetBt transport.
List of transports currently bound to the browser
The browser is bound to 1 NetBt transport.
[FATAL] Cannot send mailslot message to 'MYDOMAIN*' via browser. [ERROR_INVALID_FUNCTION]
Kerberos test. . . . . . . . . . . : Failed
[FATAL] Cannot lookup package Kerberos.
The error occurred was: (null)
When I run tests on the DNS server, no errors are reported.
BPA does indicate the following: "Cannot contact the DNS server (x.x.x.x) using TCP port 53. Check that the IP address of the DNS server is correct and that the DNS server is reachable, or reconfigure the internal and external DNS servers for the transport server SERVERNAME." The server that it is reporting this error for is the Postini server that is configured to filter outgoing messages. We configured this based on the instructions provided by us to Postini. We have tested and the server is reachable.
Any ideas what these connectivity issues could be caused by?