When Rosita gets a letter from her abuelita, Abby Cadabby realizes that she’s never received a letter from anyone! Elmo decides to write a letter to Abby himself. All he needs is some paper, crayons, and someone to help him write all the words (except his name). Also in this episode: Christopher Meloni (Law & Order) talks about mail. Brought to you by the letter X and the number 15.