They could write to anybody, either in or out of school. One of their homework assignments was to write an address book, and we provided envelopes and stamps. I luckily got to chaperone the walking field trip to the post office close to school.
Joseph only had one letter to mail, to Mimi. Can't wait to hear what it's about when she gets it! We wrote out 10 other addresses, including to his kindergarten teacher who moved to NH, but no such luck for the rest of us. He claims he wrote one to me to convince me to read Harry Potter, but since I just finished reading it on our Mardi Gras trip he didn't bother giving it to me.
I did manage to get one letter though, which came home in Joseph's backpack after school. Apparently the teacher though Nolan was being a little rude to me when I was trying to keep the kids off the ice and snow, and she had him write me an apology! (I know Nolan and his family quite well, so I actually found it quite amusing when he said "You're not my mother. You can't control me!")