Did you see your attending upload the letter? Because my attending said he would upload it asap - then I e-amiled him and said I didn't receive a confirmation. By "asap" my attending meant he would upload it a few hours later. But after he eventually uploaded it I received the confirmation immediately
So technically your attending could have said yeah i'll upload it now - but didn't really upload it until a few hours later
Anyways the moral of the story is that your confirmation should be received relatively immediately (within hours definitely less than a day)