If you are asking about Outlook Express, and not Windows Mail, the correct
newsgroup is.....
Outlook Express General Newsgroup:
news://msnews.microsoft.com/microsoft.public.outlookexpress.general
But to answer your question, /if/ you are referring to Outlook Express, you
can't turn it off, and you don't want to.
Why does OE insist on compacting folders when I close it?:
http://www.insideoe.com/faqs/why.htm#compact
About File Corruption:
http://www.microsoft.com/windows/IE/community/columns/filecorruption.mspx
Compacting your folders periodically is a must to keep OE functioning well
and at some point, you may lose all your saved messages if you don't. When
you delete, or move messages, the space they had used remains until you
compact.
See:
www.oehelp.com/OETips.aspx#2
With SP2, automatic background compacting was removed due to problems it
caused. Now you will get a prompt to compact after 100 OE closings, which
you should do, and don't touch anything until it has finished. See this for
more information:
http://www.insideoe.com/files/maintain.htm#compact
If you are fully patched, you will also now see a copy of your dbx files
being copied to the Recycle Bin as BAK files. Should something go awry when
compacting, the messages can easily be restored from this backup. A manual
compact will also reset the counter in the registry back to zero now.
For more info, see the information outlined in red here:
www.oehelp.com/OETips.aspx#2
To keep things running smooth, and for faster compacting:
Do not archive mail in default OE folders. They will eventually become
corrupt and you may lose mail. Create your own user defined folders for
storing mail and move your mail to them. Empty Deleted Items folder
regularly. Keep user created folders under 100MB, and Default folders as
empty as is feasible.
And backup often.
Backup and Restore:
http://www.insideoutlookexpress.com/backup/
http://www.oehelp.com/backup.aspx
http://www.oehelp.com/OEBackup/Default.aspx