IWAM_servername accounts' passwords were corrupted or
has been changed and out of synchronizing between AD & IIS. Reset these accounts’
passwords in both ADUC and IIS. Then run IISRESET to restart IIS.
OWA server may have difficulty to communicate with the DC. Adding the
iusr_servername & iwam_servername to the OWA server local users group may
3. You may receive
this error after upgrading the system or update security patches. Enabling
and disabling the Integrated Authentication in the IIS. Then run IISRESET.
OWA Users may not be able
to access their emails with 401 errors. The Event Viewer may have
the ... Logon Process: OWA Authentication Package:
Negotiate ... www.chicagotech.net/exchange/owaerror401.htm