Im tracing same problems in me exchange 2007 EDGE server , im getting this error on logs , any idea ? thanks Event Type: Warning Event Source: LSASRV Event Category: SPNEGO (Negotiator) Event ID: 40960 Date: 5/20/2007 Time: 12:52:04 AM User: N/A Computer: MAIL Description: The Security System detected an authentication error for the server DNS/data0.uicc0.local. The failure code from authentication protocol Kerberos was "There are currently no logon servers available to service the logon request. (0xc000005e)". For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. Data: 0000: 5e 00 00 c0

check the DNS settings on your ET server, my guess is they pointing in the wrong direction...