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I'm currently running outlook 2010 and I have a .pst file of about 25 gigs in size.

My email is currently being imported via POP3 so I am not running any IMAP or keeping a copy of email onto the server in POP3 mode.

I seem to be having more and more issues every day with the performance of outlook. At times it will freeze for 15-20 seconds while opening a new email or simply clicking reply.

I have a fairly new computer with a i7 processor. Would anyone have any suggestions on what would be causing this "freeze" and/or ways to trouble shoot to find a solution?

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Reduce the size of that .pst seems like an obvious thing to test - and its easy. Create a new one, copy over, say the last 100 messages and disconnect the big one. See whether performance improves. –  uSlackr Jun 13 '12 at 21:38
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3 Answers

up vote 1 down vote accepted

Seeing as the limit of a PST file is 20GB, and yours is 25GB I can see that definitely being an issue. It's a known issue in all versions of Outlook that anything over 10GB you will start seeing performance issues.

You can export data to another PST file to reduce the size: http://support.microsoft.com/kb/982577

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It is a well known problem with Outlook, and it can also lead to a corrupt PST eventually. Your best bet is to create a new PST. You can do this while still retaining the emails in the old one. This guide contains pretty much everything you need to know.

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Other simple way is to delete some old messages. In your case, it will be a lot of emails and then compact the outlook pst file. Another option is to create another pst files and copy all the items from a particular date; lets say prior to 1 Jan 2013 to that file and then compact your current outlook file. See how it works. Compact a file: File-Account Settings-Account Settings-Data Files-Settings-Compact Now. This will take several minutes once and safe several more afterwards :)

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The author doesn't want to delete old emails. The very fact he has 25GB of emails means he is keeping ALL the emails for a reason. –  Ramhound Feb 20 '13 at 14:08
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