You can : aggregate several rss to one, make an rss out of emails, make pdfs out of rss, send rss to mail, turn your pop account into an rss feed, make a podcast of rss with voice reading and so on.
Using email for almost everything from FTP downloads/uploads or Free WEB site hosting to using it for gatter FINGER or WHOIS information (telnet is still not available :)
an e-mail notification system that scans the entire Microsoft Knowledge Base every night, and e-mails you when updates or additions are made to the technologies you subscribe to.
cross-platform mail and news client. It is available for X11/Unix and MS Win32 platforms, supporting a wide range of protocols and standards, including SMTP, POP3, IMAP, NNTP (including SSL support for all of them) and full MIME support.
a tool that simplifies the process of compressing and sending your files online. It isn't a replacement for the traditional desktop compression tools, but its just a tool that makes things easier by cutting down all the 'krunching' hassles.
Mailing lists are funneled into news groups. Gmane does spam detection, cross-post handling, has a TMDA-fueled encryption/forwarding service, a web interface, respects X-No-Archive, supplies RSS feeds, uses SPF, features user-defined filters, more...