Letters to Santa

My granddaughter is writing a letter to Santa and she will be so excited if Santa writes back.  I found a few sites that offer email responses or printable letters but does anyone know of any other sites where they actually mail a letter? It is so much fun to get REAL mail. 
Northpole.com offers an e-mail style Letter to Santa.

Get a personalized e-mail letter from Santa from Write Santa at Home.

Send Santa your Christmas list at Write to Santa Claus.

Free printable customized letter from Santa here or here.