In some prisons prisoners can receive Christmas Gifts but the Christmas Gifts must be bought and sent through approved vendors.
You go online and do the shopping for the prisoners Christmas Gifts and then the vendor sends the Christmas gifts too the prison who then gives it to the prisoner.
You cannot though just wrap a present and mail it to the prisoner as it could be seen as unsafe or you're hiding something under the wrapping paper.
But if you do send something to a prisoner it must be something they are allowed to have and the best way to do so without worrying about the prisoner not being allowed it is to get the presents through an approved online vendor.
The prison can let you know where you can buy the presents and then they can send it to them.