Try clicking on the Hekp files within Outlook, most people overlook these
help files and they often give you the answer, you just have to do a little
digging sometimes,

Larz,
After installing Windows XP SP2, the upgraded version of OE6 is set to
compact the message store after every 100 uses. You should let OE compact
the messages, and don't use your PC until the compaction is done. By
canceling compaction or shutting down your PC during compaction, you risk
the chance that your OE message store might get damaged. And the loss of
messages might occur. At a minimum, it will start the compaction process all
over again, when you run OE the next time.

Stew,
The line " Compact messages in the background" from OE6 maintenance tab was
removed, if you upgraded to XP SP2. For many users, background compaction
caused message store corruption, and the loss of email messages. MS took the
recommendations from users to remove this feature.

I didn't find this helpful, as I have OE6 SP2, but perhaps you might:

http://support.microsoft.com/default.aspx?scid=kb;en-us;311030

I have no "check box to compact messages in the background" option
available.

Stew

I have SP2 OE6 also, and there is no provision for compact messages in the
background on mine either. Hmmmmm.
Larz

Actually, the answer is to let Outlook Express complete the compacting of
folders, assuming that the user does not compact the folders periodically on
his own. Not compacting Outlook Express' folders will eventually cause
corruption and will render all of the user's data useless.