This utility can create a backup or an archive of your e-mail messages in Outlook Express folders. It can back up multiple identities using on-the-fly compression. This supports automatic media spanning and has an automatic backup scheduler. You can backup as a self-executable EXE file, this feature allows you to backup your data in the form of a standalone EXE file that can be executed on any machine even if Outlook Express Backup is not installed. It supports backing up the data of all the identities in Microsoft Outlook Express in the same backup file.
More info:
hxxp://www.genie-soft.com/products/oebackup/oebackup.html

cool piece of software, and needs $$$ for that.
what i am doing is exporting those emails to a Outlook PST file. :)