Term used to describe a joint rolled by sticking two different brands of rolling papers to make one multi-colored joint.
The first named example of a mailbox joint was rolled with one RAW organic 1 1/4 rolling paper and a JOB 1.25.
Last night was insane, I matched with my uncle and his stingy ass made sure to weigh the bud to the milligram. He was tweaking so hard that we had to roll up a mailbox joint using one of each of our papers because he quote "didn't want to waste all the RAWs"