As mentioned there are items like cheese that can't take heat or it melts so gotta cold smoke it.
Also dishes like salmon lox and other cured and/or cold smoke fish and products.
Lots of people only do cold smoked bacon and it only gets heat or cooked when it hits the skillet.
So basically a mailbox mod allows you to separate smoke generation from the MES heat generate and have greater control overall. Additionally if using the A-Maze-N Pellet Smoker (
AMNPS) tray you can get up to 12 hours of perfect Thin Blue Smoke (TBS) without having to do much fiddling or baby sitting. So, greater control and smoke production with little to no babysitting effort.
With a mailbox mod you also don't have to open the door if wanting to use the
AMNPS tray or a tube you just pop it into the mailbox mod and if there are any pellet flame up situations (this will happen on occasion, usually wind gusts or windy days) then the flaming up is contained separate from the MES and food. Easier management of all kinds of things.
Additionally with the mailbox mod you aren't generating as much heat in the MES box because there is distance between the burning pellets and the food so helps with maintaining cold smoke temperatures, which can be a problem in hot climate areas like TX, AZ, FL, etc.
Cold smoking can give excellent flavor to dishes but it's something you have to be prepared for and want to take on. I personally have only cold smoked fish and if I wasn't so lactose intolerant I would cold smoke some cheeses. I hot smoke my bacon to 145F (safe to eat temp) using the sausage smoking process to avoid melting out fat. I do this because I love eating the pork belly as I'm slicing it and honestly I eat like 90% of it like it's a bacon Cold Cut, sooooo good!
Anyhow, as you can see there are many possibilities here but I hope this helps answer some questions about cold smoking and usefulness of a mailbox mod with burning pellets in an
AMNPS tray or tube :D