Eudora Archiving
Eudora has serious problems as an email client, but software that can send and receive email is trivial. The real trick is making sense of what you've received, and Eudora is still better than anything I've ever seen for archiving, filtering, and searching email. I'd pay a lot for a version that just imported and stored.eml files (or whatever) from a client, rendered them properly, and retained all the archival and customization features.
Biting the hand that feeds IT
