Before the days of everyone having ring cameras or other sources of home security the mailbox drop was a good way to do it. According to an ex LSU bagman I met in a bar many years ago they would simply drop off a plain, unmarked envelope filled with cash in the proper mailbox, then shortly after someone would call the player or family member contact to chat, talk about how great it would be if they (or their kid) played for (insert SEC school) then towards the end of the convo casually ask if they had gotten their mail for the day...and if not they should check it out asap. The last part was to make sure they know who it was coming from, yet no paper trail that would give them away. According to this dude it was so common at one point in time they had to stop using it in some cases and go back to direct handoffs. No, not because the NCAA was aware, but rather relatives/friends/acquaintances of highly sought after recruits knowing about this method and going through the kids parents mailbox looking for unmarked envelopes to steal.