I started to contact my professor for recommendation letter in mid-Nov, and he replied a month later, explaining that he was busy with final exams and was happy to provide me a recommendation. I should have been alarmed by then but instead, considering he was quite a successful senior chief financial manager, which would add up a lot for my application, I listed his name for three most important programs. However, he seems to be unresponsive for all of my follow-up emails. And since he is an adjucnt professor from my exchange school and it is summer vacation now, there's no way that I could ever meet him in person and I cannot call him up as well as I don't have his personal phone number (And I believe it will only make things worse by calling him). I am totally freaking out and I wonder if anyone has any good idea for my situation.