Ok something is screwed up with your outlook express.
Try this workaround for backing up mails,
1. Restart windows in safe mode.
2. Close Outlook Express.
3. Click Start, Find, then Files or Folders.
4. In the Named box, enter *.dbx
5. In the Look in box select, or enter, your system hard drive (usually C🙂.
6. Click Find Now
7. You should now see a list of your Outlook Express mailbox files.
"Inbox.dbx", "Outbox.dbx", "Sent Items.dbx", "Deleted Items.dbx" and "Drafts.dbx". Any additional mail folders you have created in Outlook Express will be displayed with the ".dbx" extension.
8. Highlight all the mailbox files that you wish to back up and copy them to another location such as a floppy disk or an appropriately name folder.
9. Close Outlook Express
Using steps 1 - 6, above, identify where your ".dbx" files are stored in Outlook Express, and copy your backed-up e-mail folders to this directory, ensuring that you overwrite any existing files.
10. <--- Rate me in my profil 😀
edit: typo