Troubleshooting Outlook Express Outbox Issue

To delete the individual problem message, you would have to open the out-box.

You can't do that, but you can eliminate the entire corrupted out-box.
1. Start Outlook Express, select
2. Options from the Tools menu,
3. Click the Maintenance tab, and
4. Click the Store Folder button. This will give you the location of the files that represent your e-mail folders.     Copy this location.
5. Close Outlook Express, open Windows Explorer, navigate to that location, and
6. Rename the Outbox.dbx file to Outbox.xxx. Double-check that you can now compose, send, and receive messages normally.

Outlook Express recreates the out-box as soon as you compose a message. Now delete Outbox.xxx.