I think (?) you will find it a lot easier to design and build if you just submit the message body in an http form, and let a servlet on the server side do any actual emailing (I think there are lots of examples, of servlet code doing JavaMail API, here). Otherwise you have to figure out how to sign an applet and give it authorization, to try and connect to an SMTP server, worry about the client running behind firewalls, worry about the SMTP server accepting connections from the random client host in the first place, etc.