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...
application that tells you when your emails have been received and opened. It works alongside your existing mail program, sending you an email the moment your message is viewed
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.