It depends on the gift! Anything dangerous won't get through, but if he just writes a rude message that could easily get to her.

Cards and gifts are sent directly to Samantha's house so unless he's intending to break in, he'd have to go find someone who is planning to send her a gift before they send it. That would be easy to do with a gift from the East End Pack (...does he really want to sabotage Katherine's gift) but would require discussion with any other characters who are planning to send anything.