Too much transmission fluid?

What happens if you have too much transmission fluid in the car? I would think nothing since the only thing between the transmission and the outside is that dipstick tube with a little o-ring seal, but I don't know. The reason why I am asking is because it doesn't matter if I check the level when the car is warm or after it has been sitting all night; there is always fluid all over the bottom of the dipstick (from the tube I guess) so I can't check it. I added two quarts because I know that I'm at least leaking a little bit from the hoses (supposed to be replaced by the filiter recall but was never put on). It at least seems to shift slightly better now.