Hey does any one know what the "s" stands for in wonder mail s?

It's the rank, so the mission is "S" rank. Ranks range from "E" to "10*" I think.

it's not the rank. It's the name or something.

Wonder Mail Sky seems obvious.

In the last games, it referred to the rank of the mission, or the rank you need to take on the mission so I would assume it means the same here. But, the fact that everything is a Wonder Mail S code, it could be what Benedict stated to differentiate between the titles.

I agree with what Benedict says, it makes more sense.

Yeah so do I.