DIAGNOSIS This is almost always condensation, not a leak. Humidity from the water pan condenses on the cold interior walls and door, then runs down to the bottom lip and drips off. It is normal, but excessive drips indicate overfilling.
FIX 1. Do not fill the water pan beyond the 3/4 mark. 2. Use hot or warm water in the pan when starting a cook. 3. Ensure the smoker is level. Tilt can cause water to pool against the door seal.
IF THAT DIDN'T WORK The drain hole on the left interior wall (behind the water pan bracket) may be clogged with grease or debris. When cool and unplugged, use a pipe cleaner or small brush to clear this hole. It allows condensation to drain properly into the drip pan.
HEADS UP The drip pan under the heating element is for grease, not water. If the water pan overflows or condensation is excessive, liquid can flood the grease pan and cause splattering or smoke. Empty the grease pan regularly.