I ended getting a wild hair up my butt this morning and did the mailbox mod. It is working like a charm. However, I am not getting enough air in the cabinet and all my smoke pours out the mailbox unless I have door cracked. When the door is cracked I could get tbs all day long. I am thinking I just need to add another vent in the smoker since the only one on my smoker is on the rear upper portion of the cabinet. So here is my question. Where should I put a new vent to where it will have the same affect as having the door cracked and it will help pull the smoke from the mailbox?