One other thing that can occur which is rare, is when the tranny case itself has a case with a poor casting (case porosity) where the fluid can leak right through the pores in the case.
Next time you take the pan off, put the edge of the pan over a block of wood with the tranny side of the flange facing up, use a ball-peen hammer and tap the holes flat or even out the other way. Do that to all the holes and lay the flange side down on a good flat surface to see if all the edges are fairly flat.
when you install the pan with a new gasket, tighten the bolts to 10 lb/ft or if you are good with the feel of a wrench, snug them up just enough to hold the pan tight against the tranny case.
Look at all the other areas the rest of the guys mentioned as well. You may want to take the thing to a car-wash and clean it real good. See where it is starting to leak when you get home.
Also check the front pump bolts. you will only be able to get to a few of them as the torque convertor will be in the way. If some are loose, others may be also.

There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
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Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!