So if I was in your shoes, and the texting and email persisted AND IT WAS BOTHERING ME...I would write "Guy, thanks for all of the attention, but I do not like the frequency of texts and email. Please, stop altogether."
I know you haven't read all this thread Greek, (having a nice vacation I hope), but I posted this link about thwarting potential stalkers.
I agree that she may need to directly say 'stop' to this guy, but I would NOT thank him for the attention nor say anything which suggests it is simply the frequency which is the problem.
He may just be clueless and annoying, but there is also a chance he could be dangerous. Better to err on the side of caution IMO.
