Right. So. BS Johnson, sometime before 'the end' for the post office invented a better sorting machine by making pi exactly 3. This caused quantum (twice) and they started getting letters to send before they had been written. Some wizards who used lingo that makes me think 'Ponder and pals', thought this was brilliant, but then it all got to be too much and they started recieving letters that only had the possibility of being written (Ponder, in his Reader of Invisible Writtings capacity must have had an orgasm). The wizards advised not shutting it down, lets it destroy the universe, but them one of the postal workers got fed up and shut it down anyway. The wizards declared the universe had been destroyed, and then remade in the same second, and you could tell by looking.

It sounds to me like we could say this happened, and when it was remade, the post office had been in ruin for years. Trousers of time sort of thing.