In some cases, Exchange is not to blame if something does not work. Problems also occur on the client. Finding these is not always easy, as there are often many different programs installed on the client. Plug-ins or other software can affect communication with Exchange, but often none of this can be found in the event logs. However, there is a way to activate logging for Outlook in order to better localize the error.
This activates the log mode for Outlook 2010:
File -> Options -> Advanced -> Activate logging of troubleshooting
This option is active after restarting Outlook. This key is generated by ticking the box:
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail\
dWord: EnableLogging = 1
The log file for SMTP, MAPI and POP can be found here:
%Temp%\Outlook protocol\Opmlog.log
The log file for IMAP here:
%Temp%\Outlook-Protocol\IMAP-.log
The log files may contain error codes that make troubleshooting easier. A list of MAPI error codes can be found here:
http://support.microsoft.com/kb/238119
