You can get a free pop3 account with
www.softhome.net - it has a few restrictions buyt the fact that it's pop3 should get past your firewall problems.
It's a while since I've been there but I believe
www.f*ckmicrosoft.com (be creative with the asterisk) do some free accounts of some kind.
Personally i use
www.eudoramail.com - I find it meets my needs pretty well.