A rather plain, white envelope with "804" printed on the front in blocky writing.
Inside is a note written on plain computer paper:
"To the person currently stalking 802,
Somehow you think your sick gifts and creepy letters are earning you friendship. Here's a tip: it's not. He's not your friend, he won't be your friend. He especially won't be your special friend, creeper.
And I will keep making sure he won't be your friend.