It goes nicely along side the house. Cardboard Mailbox Craft - Like the cardboard house this project isn't really intended to be made by young children but they will love playing with it. My child has a hard time waking up on the right side of the bed after her naps. I find that if I put a little surprise in her mailbox while she is sleeping and ask her if the mailman came when she was sleeping she goes from nap time to wake time with a lot less hassle. It is also a great teaching aid.
Children love to copy their parents.
Show them how to write a letter put it into an envelope lick the flap address it stamp it and mail it. They love to do this over and over. If you have a wagon or push cart have your child be the mailman and have him deliver your mail to the mailbox or to another member of the family. Make up little notes to your child and put them in the mailbox. They will love opening the letter and listening to you telling them what it says.