Sylpheed: Eudora, Outlook, Outlook Express and the rest of the commercial e-mail clients can take a hike. I love this baby and the best bit is she comes for free and boy is she fast. The GTK thingie looks kind of clunky on Win 32 [it is still bleeding edge beta code they say, but runs steady enough for me] but it rocks on KDE on Linux. Just one negative point though, it does not yet let you have identity logins on either Win 32 or Linux, which is the only reason why I still use Outlook Express at work till date.
Yahoopops: Do not want to pay for POP access to Yahoo! mail? Miss the old days when you could check Yahoo! mail using Outlook or other e-mail clients. Then this nifty app is the one for you. It sets up a tiny server on your system that connects with the Yahoo web interface and the rest is like the good old days. I am not sure how legal the app is, you would have to check Yahoo's ToS for that.
Another interesting tidbit is that Sourceforge, where the project is hosted, mentions a Anuj Seth and a K Shyam as the developers behind the project. Do I smell a story possibility for the Rediff team? ;)