Sorry, but do you realize how long I've been dying to read this discussion?
Anyway, I don't think there was a real problem here. I _always_ thought, even before _GP_, that what Ankh-Morpork had was a very informal messenger-service system rather than a proper post office. Haven't there been references to things like handing a letter to someone who happens to be going in the right direction and hoping that it somehow gets there? And _GP_ makes it clear the "mail coaches" were not really the Postal Service, just a coach-for-hire service using the old Post Office equipment. Therefore canonicity is saved and the universe does not explode, QED.
no subject
Anyway, I don't think there was a real problem here. I _always_ thought, even before _GP_, that what Ankh-Morpork had was a very informal messenger-service system rather than a proper post office. Haven't there been references to things like handing a letter to someone who happens to be going in the right direction and hoping that it somehow gets there? And _GP_ makes it clear the "mail coaches" were not really the Postal Service, just a coach-for-hire service using the old Post Office equipment. Therefore canonicity is saved and the universe does not explode, QED.