- Agents 82 through 85 are killed aboard the Orient Express carrying the payroll for CONTROL's freelance agents behind the Iron Curtain. First Agent 99 and then Maxwell Smart are then assigned to the mission [Episode #13: "Aboard the Orient Express"].
- Max evidently has played courier more than once as he has a "courier chain" as part of his equipment [Episode #23: "I'm Only Human"].
- Agent X is dispatched to Greenland to deliver a new code to CONTROL's communications center there - a mission considered so important that even his number is top secret [Episode #37: "The Decoy"].
- Agent 38 is apparently on permanent courier assignment. He - or actually his KAOS double - complains that "We couriers never hear anything. We're like errand boys." [Episode #63: "The Spy Who Met Himself".]
- The courier department has at least twelve members since Max meets with a Courier 12 aka KAOS's "Wailin' Wanda" [Episode #75: "The Groovy Guru"].
- When five couriers on the same run - including Busby who was being guarded by Max - disappear in midair without a trace, everyone transfers out of the courier department Episode #89: "Closely Watched Planes"].
- Agent 99 complains that the so-called precautionary measure of taking her off dangerous assignments and relegating her to elementary courier duty while she was pregnant has continued six months after the twins were born and she is still doing "unimportant courier work" [Episode #126: "Moonlighting Becomes You"].