Well we had an interesting problem this week. For some reason all of a sudden, users with Outlook 2010 started to have the application crash when they tried to open the application. Outlook would open fine in safe mode and if the user re-created their mail profile everything would work fine - until they rebooted.

After a reboot Outlook would again crash with an APPCRASH error with the culprit being olmapi32.dll.

Most of the information found during Google searches pointed to corrupt OST files, or corrupt olmapi32.dll files. Neither of these seemed the case as the mailbox would open in Outlook Safe Mode.

Come to find out we had a "Safe Senders" List that can be setup via Group Policy in Active Directory. This list worked just fine on Outlook 2003 and 2007, however it seems that Outlook 2010 has a problem with this either Group Policy or list (which is just points to a text file on the network with a list of "safe" domains for use in Outlook's Junk Mail Filter).

Once we disabled the Group Policy and rebooted, Outlook would open as normal.

So if you have an issue such as this one, check your Active Directory Group Policy and disable the Safe Senders List as a temporary workaround. We haven't checked with Microsoft about this issue as it is not very pressing, but if it is for you and you have a support contract, you may want to get Microsoft involved.

Good luck,
Flux.