When we take large batches of letters to the post office, we need to have them sorted by zip code. If we are running letters for the entire district, we will need this sort option when printing letters. We also need the ability to sort printed letters by school. Currently a copy of the letter is supposed to go into a students file, so we need to be able to easily divide up the printed letters by school so that they can be sent out for filing. No school is going to want to print 150+ letters one at a time.