Ethics Focus: "It's Only a Birthday Card

Short Answer

Ethics Focus: "It's Only a Birthday Card"
You have worked at the state prison for five years. There is an inmate you have known for four of those five years who works in the security office. He has asked you to mail a birthday card to his niece, Sarah, who is not on his approved mailing list. You have observed other correctional officers mailing cards and letters on occasion for inmates to persons not on their approved mailing list. You really don't see the harm in a birthday card for a niece. Still, she isn't on the approved mailing list.
-What is the worst possible consequence?