Mai is not really a character to get into too much trouble with getting air attacks. she has a very quick jump and her s.hp is pretty good. It seems to me its the stand off close quarters situations like open her up for an aerial attack. This occurs with characters like sagat (jump lk) and yamazaki (jump hk).
It seemed that my best defense for these jumpins was a strait jump air grab. It seems quick like a dragon punch but also has the ability to hurt empty jump k-groovers.
I want this thread to be about the power of her air grab , and all the other air goodness of mai, I will edit this post to compile a list of what each groove adds to her aerial prowess and a seperate list of what annoying jumpins her air grab can thwart on reaction.