At a client, the exchange server stops responding every other day in the middle of the night. All Exchange services stay running but it looks like there are some MAPI issues in the event viewer. Restarting the services brings everything back to normal, but it still happens every other evening.
Here is the event in the log:
The description for Event ID 1009 from source MSExchangeIS Mailbox Store cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.
If the event originated on another computer, the display information had to be saved with the event.
The following information was included with the event:
/o=XXXXX XXXXXX/ou=First Administrative Group/cn=Recipients/cn=euser
First Storage Group\Mailbox Store (XXXXXX-MAIL)