[ApK]

Gregg, pick a brand for yourself, even if you can't get get greggbell.com specifically. Consider GreggTheAuthor.com or BellBooks.com, or bearstardiode.com (whatever that is??) or similar. But makes sure it's something you can live with. Domains are cheap. You can have several. But best to pick one and only one to use for email and NEVER CHANGE IT AGAIN. ('til Internet 2.0, anyway.) Then you can point or forward that domain to virtually any email system that you want.
As far as the email service itself goes, I've been very happy with Gmail. I'm on the no-longer-available free Google Apps package, but I like it enough that I'd probably start paying if forced to, rather than switching.
Don't tell them I said that.

ApK

p.s. What I mean by "never change it" is pick one that you want to use for email and try not confuse people by doing "change of addresses." You can have several domains, and they can all route email to the same place, so even if you temporarily started using greggbell.net, and changed all your social sites, etc, you could eventually start using your ideal domain when you get it, but ALSO keep greggbell.net working, so you while the new address is on your website, book jackets, etc, the old address still works, too, and you don't have to notify anyone of the change unless you just feel like it.