The weekly reading of viewer mail began with the presenters (Cat, Ant and Dec)) along with that weeks guest and theaudience dancing to the song "Please Mr. Postman" by the Carpenters. While not strictly a sketch, there were several moments of humour and sketch-type gags in its run based around the mail they received, and sometimes the absence of it (which often was revealed to be a hoax).
One segment (during an 1 April edition in 2000) ended earlier than usual when Dec (appearing slightly ill) collapsed onto the floor unconscious during the Postman dance; after a few seconds, the programme immediately went into the second half of a Pokémon episode. The incident was later revealed to be an April Fool's joke.
Another famous incident occurred when Ant was asked to read out a rather crude anecdote, and started laughing uncontrollably, causing Dec to fall into hysterics as well. This clip has since been replayed numerous times since, due to it being considered an 'outtake'.
Yet another Postbag incident occurred during the run of the first few Pokémon episodes, when a letter was received from a viewer telling the presenters it was pronounced 'Po-KAY-mon' and asking them to pronounce it right. However when the second half of Pokémon was played (the episode being "Bulbasaur and the Hidden Village") and one of the show's characters pronounced it in the same way the presenters had been for the past few weeks the cartoon cut back to the studio where Dec demanded to see the cartoon clip again, and upon seeing and hearing it being pronounced 'Po-ke-mon' proceeded to have a small (mock) rant to camera about the letter and the pronouncement while ripping the letter up. After this the second half of the episode was played. It is unknown whether this incident had been planned beforehand to make a point or not.
Later Postbag segments ended with studio performances of viewers' songs about the show.