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Outlook 2007 Archive issue


We have a user who's mailbox .ost file is 23GB. We recently tried to create an archive on an external drive (they have an older computer with small hard drive). The process took several hours and, once completed there was an 8GB file on the external labelled as 'archive.pst' which was 8gb. Now the issue we have is that the original 23gb mailbox file is still the same size even though it now only displays 30,000 of the original 90,000 messages.

I have a few questions:
1) How can we reduce the size of the primary mailbox folder?
2) Is there any reason why the archive file would only be 8GB even though it contains rougly 2/3 of the content of the original mailbox?
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Yes the OST may have slack space that would not be in your new PST file, also PST might be more efficient? Don't know, maybe. Also be aware that the .ost is not actually a mailbox file, it's a cache file, mirroring the mailbox on the exchange server.

Sorry, missed your first question, you can try deleting (or renaming if you're uncomfortable deleting) your OST file and let outlook re-synch with exchange. It will automatically rebuild the OST next time you connect to the exchange server.
Outlook data files (both PST and OST) never shrink in size on their own. They keep a record of any deleted items, so deleting mail never decreases the size of the storage file. Assuming that you didn't miss anything while exporting that file to a PST, that's the reason that the PST is so much smaller than the OST -- it only exported the current data.

If you want to shrink the original OST file, you can tell Outlook to compress that data file. Right-click on the user's mailbox, click "Data File Properties", click "Advanced", go to the "Advanced" tab, click "Outlook Data File Settings", and cick "Compact Now". This process will probably take longer than the export did, but the file should be much smaller when it's done.
dkuhlmanAuthor Commented:
btdownloads7 - Will performing the 'compact now' operation cause any permanent loss of information in the mailbox? I know that the user would frequently check relatively far back in their mail history and want to make sure that their experience won't really change apart from the size of the mailbox decreasing.
No, it only removes the "permanently" deleted items. Nothing that actually shows up in any of the folders will be removed.
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