Fidolook
- Freeware extension that provides enhancements and capabilities for Microsoft Outlook Express. Provides templating and customization, access for working with raw headers, folder options and allows importing and exporting of messages.
- http://www.fidolook.org/

OE-Backup.
- Backup and restore utility for Outlook Express 5 and higher. Backup mail folders, mail accounts, message rules, signatures, stationery, and all personal settings.
- http://www.oe-backup.com/

Stationery by Teresa
- Outlook Express stationary files.
- http://www.teresasstuff.com/Stationery/stationery%20index.htm

OE-QuoteFix
- Add-on that modifies message composition windows on-the-fly to allow for 'correct' quoting, compressed indentation, and RFC-compliant signatures.
- http://home.in.tum.de/~jain/software/oe-quotefix/

ABF Outlook Express Backup
- Backup and synchronization tool for Outlook Express mail client. The user interface is multilingual. English, French, Russian, and Macedonian languages are supported.
- http://www.abf-soft.com/outlook-express-backup.shtml