Which Generation MES do you have? Glass door?I've done 2 smokings with a masterbuilt 30 from Basspro. I've had leaks at front right corner both times. I live in Houston so outside temp not a problem; unit is level. Both times smoked with vent closed; thought that was what I was supposed to do. I am concerned with the bottom rusting out.
It's kinda like when a roof leaks, and it's dripping through the kitchen ceiling. That doesn't mean that the roof is leaking right above the kitchen. It could be leaking on the other side of the house, but coming through over the kitchen.
Here is where mine is leaking.
The outside temps were 14 degrees.
I smoked for six hours on Super Bowl Sunday and had no further leaks. Opening the vent fully must have helped.