I have several clients that have large Outlook 2010 Exchange databases. One in question is about 39GBs. However, when checking on properties and folder size, the local and server folder size is actually only about 24GBs.
Per Microsoft's documentation, Outlook is mean to autocompact itself when the computer is idle and will only leave about 5% of "white space" for performance reasons in the Outlook Database.
Doesn't look like its doing it, maybe its because the database is too big and to compact something like that on a regular basis to clean it up would be a very time intensive job.
Or Outlook doesn't think the computer is ever "idle". I guess the question is, what is "idle" in this case? Could an online backup in the background think that its not "idle"?
Does anyone know if Outlook 2013 does a better job at keeping down the size of the Outlook Database? I noticed the other day when I set the slider for one user from keeping 1 year to 6 months of cached data it immediately reduced the database (.OST) by a large chunk, immediately cleaning up space. I'm wondering if this is also the case for the continued maintenance of the database or not. Any insight would be helpful.