Everyone knows that Santa lives at the North Pole, so of course any letter from Santa should include a North Pole postmark. Fortunately, Santa has plenty of elves (and some U.S. Postal Service employees, too) to help with this task.
To get your Christian Santa letter canceled with a North Pole postmark like the one pictured on this page, simply place it in a regular envelope and stamp and address it in the regular fashion. Then place that envelope in another one and address the outer envelope to:
North Pole Christmas Cancellation
4141 Postmark Drive
Anchorage, AK 99530-99998
Be sure to mail it early. To ensure delivery in time for Christmas, the postal elves in the North Pole will need to receive both envelopes by December 15.