yes he does. if آپ check on youtube, alot of people have uploaded ویڈیوز of them screaming about his reply. He personalizes them too. :) Kristen also جوابات to fanmail.
here's a site where people رپورٹ that he replies.
link But it does take a while. I'm sure he gets tons of fanmail. And since he's still filming his new movie "Remember Me", he probably hasn't had much time. But from that site, he's still replying! From the looks of it, it takes about 5-6 months for him to reply. But understand he probably gets ALOT of fanmail.