I am finally getting my US citizenship, ceremony on 20th of May, so I will apply to dental school on 5/21. I am taking DAT on 6/30. The problem is... I do not have enough letters... I have following letters in my letter service, 1 dentist, 1 science, 2 research and 1 humanities. I still lack 1 science letter. I have asked my science prof january 2008, but he still has not sent it in. I had my GSI draft it and he even told me that he gave it to my prof, but still nothing for 3 weeks. I think right now is totally inappropriate time to ask my prof to send the letter because he is busy with writing final exams and grading (he lectures 700 students). I gave him a deadline of may 15th, but I don't see that happening anytime soon. so, what I wanna know is when the latest time would be to send the letter to aadsas (I am sending it to letter service then forwarding it to aadsas just in case I don't get in this cycle). How long does it take AADSAS to process the letter of rec received by mail?