On the iMac in question, running OS X 10.11.3 and Office 14.6.1 (I believe), when Outlook is started for the first time after the Mac has been rebooted it spends a long time "Setting up identity" - between 10 & 15 minutes. Subsequent quit & restart of Outlook sees it open up in less than 10 seconds.

Activity monitor shows the Microsoft Database Daemon doing quite a bit of work reading from disk. My assumption is that it is performing some sort of verification of the database. However there are no "backup" identities being created - which to my mind says it is not doing a full rebuild.

Outlook is connected to a single Exchange account and other machines running same versions of OS X and MS Office and connecting to the same exchange account do not exhibit this symptom. The Exchange account is quite large - approx 27GB.

My understanding is that it is not a good idea to rebuild an identity that contains an Exchange account because there may be unwanted changes that get pushed back to the Exchange server.

My Google search has shown up at least one other case of this happening but no resolution was noted so that hasn't helped me.

This symptom was observed on the iMac of a client of mine - so I'm not easily able to execute various troubleshooting steps ad-hoc.

My best guess is that there is a permissions issue on cache files? But I'd love to have somebody give definitive info :-)

Thanks,

Kiwi Graham