So I decided to try making my own Mailbox smoker. I built a platform and got a mailbox and a 3" flex elbow from Lowes for under 20 bucks. I made a ledge on the side for the mailbox to fit into so I can remove it and revert back to stock if I so desire. After testing it out yesterday with my Amazen Pellet smoker to season it, it wasnt getting enough air flow so this morning I took a small fan out of an old external hard drive case and drilled a 1" hole in the back floor of the mail box and mounted the fan on stand-offs over the hole inside the box so it can draw air in and create a positive flow. This worked great and only really need it to be on for the first 1/2 hour of smoking. After the first 1/2 hour there was enough airflow and the APS was burning solid and had the infamous TBS.
Sorry I don't have a picture of the fan in the mailbox, took these yesterday and now waiting for my Ribs to be done. I'll add more pictures soon of the fan, and the removable "Keyed" mount for the mailbox