On the previous Friday, I discuss or send home a note with the parents that the following week is about the post office. I previously have decided various colors for various students. I then give that color paper to the parents with a sheet of stickers (for stamps). The main concept is the parents write letters over the weekend to put in our mailbox when they drop their child off. During mail time (snack time) the students can check the mail–color coded. As well at the end of the day, the parents can check the mailbox for letters (pictures) back from the children (color coded).
You will need various sizes and weights of smaller boxes and a scale to weigh them with. Add this the dramatic play area along with magazine subscription stickers for stamps. As the children weigh the packages they can add the necessary postage. This is particularly fun if there are other postal sites in the classroom for delivering the packages. You can even work together to come up with postage costs; site A will cost…. site B… and so forth. Having some sort of mail bag will also be helpful and fun!
In my four year old preschool class, we let our children “write” a letter to themselves. We explain the form of writing a letter with a salutation, body, and signature. We have a pre-made worksheet for them to use. We let them (with lots of help) address the envelopes, affix a stamp, and then put the letters into our schools mailbox. They are so excited to get to school and tell about the letter they received days later. We also try to schedule a “field trip” to the post office the day after the mailing. This way the children get to travel with their mail to see how the system works.