If that's the case, then send them an empty envelope from an anonymous source!
I'll write their address on the front in beautiful calligraphy, so they think they're getting something special.
Then, when they open it to find there's nothing inside, they'll be shocked, confused and creeped out.
This works particularly well if the recipient is based in a different country to me (I'm in the UK), as a foreign stamp will make it all the more confusing!
All I need is the address of your recipient, then I'll send off your envelope straight away.
Your envelope will be dispatched on the day of your order, and estimated delivery times are as follows:
UK - next working day (incl. Saturdays)
Europe - 3-5 working days
Rest of world - 5-7 working days