<shameless apple plug>
I use Apple's Mail.
I've used so many Mail clients. At the end of the day, they're all the same. They all have their shortcomings and flaws. But, I use Apple's Mail because it's easy, convenient, and works seamlessly with .mac. I need my mail synced between my MacBook, my mac Pro, and my PC at work. And yes, it just works!
</shameless apple plug>
northy124
Not another one of these threads, can't you search?
Currently I used @mac.com since it sound more professional,
Gmail is brilliant. Love the web interface, love the mobile phone application for email on the move, and love the ability to use pop3 with Mail.app
And my old hotmail forwards everything to my new gmail.