Must say I like the way Gmail works.... it stores emails in 'conversations', rather than single emails, so you can follow a series of emails really easily. Loads of storage space, can add large attachments...
I'm sure someone will moan about it spying on you or something though... but to be honest, Its not really a concern... I'm hardly sending top secret MI5 evidence across the UK (Y)
Edit: Ok, buy yourself a domain name then.