Eudora is a great e-mail application, but it has one odd quirk. If you sort outgoing mail (as I do with a separate sent messages folder for each client), there is a ten-second delay between when you send the mail and when it is sorted into its proper home. First the message will appear in the general "Out" index. Then, it's as if Eudora re-scans the header to determine that it fits a sorting rule, and the program moves it later to its proper place.

This seems slow and inelegant given the innumerable other complex information tasks that take place instantly with today's technology. But at least Eudora has the sent-mail sort option. It's the main reason Eudora is my choice for work email; Apple Mail, while excellent in other ways, just doesn't do it for serious use.