Related Pages

RSS Feed Knowledge Base Feed

Page Options

Outlook express auto compacts email messages

Problem Description:

Sometimes when you close outlook express you get a message saying that folders are being compacted.

This seems to occur at random, and you did not request for a compaction, or do anything out of the ordinary to cause it.

Cause of the Problem:

When Windows XP Service Pack 2 (SP2) came out Microsoft changed the behavior of how Outlook Express handled automatic compaction of messages.

Prior to service pack 2 Outlook express automatically compacted messages in the background if the program was idle.

After service pack 2 Microsoft changed the behavior to auto compact messages every 100 times the program is closed.

In addition Microsoft also removed the option to turn off automatic compression of messages, forcing the program to compact every 100th close.

Your Ad Here


There are a couple of ways to work around this issue, however we have yet to see any of them stay after reboots or closing of the program. This is partly due to Microsoft using the compression feature as a way to force checking of the outlook express database.

Option 1: Adjusting the Registry

You can go through and set the number of closes until outlook express will perform an autocompact.

Change the registry value at: "HKEY_CURRENT_USER\Identities\{GUID for Identity}\Software\Microsoft\Outlook Express\5.0\Compact Check Count" to be 0.

This will basically tell Outlook Express to never perform the check. We have seen this registry value become reset. Likely due to Outlook express updates, or the program seeing that the value is incorrect.

Option 2: Perform a Manual compact

Supposedly performing a manual compact on all folders resets the above mentioned counter delaying it for another 100 openings.

This can be done by going to File -> Folders -> Compact All

Option 3: Switch email clients

In any of the above cases the autocompacting does not actually get turned off, and Outlook express will still attempt to perform a compact.

If you wish to completely avoid this compacting behavior you will need to switch email clients. We recommend Mozilla Thunderbird. Whatever email client you wish to use, be sure that it can import your old outlook express email, and address book (unless you just want to start fresh).

Related Programs and Devices:
Outlook Express , Windows XP , Service Pack 2 , Thunderbird , Windows 2000

Last Updated: 01/09/2009 11:05 PM

blog comments powered by Disqus