There's a therapist with a Second Life practice.. I dunno if you do SL, but if you look up Avalon Birke on there, she's a real life therapist too, but she's got this little counseling center and stuff on SL. works a lot like real life therapy, I think. Most SL stuff tries to work like real life, just with pixel-people.
I dunno how e-mail type therapy would work. SL is closer to RL than e-mail is.. sorta.. lol