Create an imaginary play post office with preschool children by using a table as a counter for customers and providing them with envelopes to use along with stickers for stamps. An old cardboard box can be painted blue and turned into a mail drop by having an adult cut a slit in the box that allows children to place their finished letters in the mail slot. Discuss with children the different roles people have within the post office and then encourage children to take turns playing in the imaginary post office, being the postmaster, counter helper or customers.
Children can write a letter to their parents and actually mail it to them with a real stamp. Help preschool children write a letter, or allow them to practice their letters on their own, along with drawing a picture to send. Once the letters and pictures are finished, children can fold the papers and fit them within an envelope along with licking and sealing it. Discuss with children how a letter can't go through the mail without a stamp and address. Provide each child with a stamp and allow him to press it in the upper right corner of the envelope. Help children write their home address on the front of the envelope. If there is a mail box located at or near the preschool, children can place their addressed and stamped envelopes in the mail box and wait for them to arrive at their home.
Mail carriers have large bags that they use to carry the mail when they are on their mail route. Look at picture of mail carriers with preschoolers and discuss how they wear uniforms while working. Children can create a mailbag to carry letters by using brown construction paper and a length of string. Children can fold a sheet of 9-inch by 12-inch construction paper in half and glue the left and right sides together creating a pocket that is open at the top. Using a black marker, preschoolers can write "mail" on the front of the pocket and then use pieces of tape to secure a piece of string to the sides.