If you're not aware of it already, you might want to keep an eye out for Mailpile, which should have a bunch of the features of GMail (web-based, labelling, spa

If you're not aware of it already, you might want to keep an eye out for Mailpile, which should have a bunch of the features of GMail (web-based, labelling, spam filtering) while being open source and allowing you to run it yourself (I'm sure hosted versions will pop up as well).