Hehe! Who said that was a letter from the Scarlet Man? The wax seal is traditional, anyone can use it . It's the insignia on the seal that distinguishes the sender. Each prominent sender has his own seal, which no one else may have, usually engraved backwards on a ring. The unique seal is like a way of proving that the letter isn't a counterfeit: only the sender can access that special seal.
I didn't draw any seal clearly, leaving it to the imagination who sent the letter (or if it's a letter from Lucky waiting to be sent).
@Annaliese_Dancemuddle I'm really sorry, I have too many requests at the moment so right now I can't promise anything.