Future Letter
Future Letter is a website that allows users to write a letter to their future selves. The website has a simple design. Just type your message, select a time frame, and click “configure.” The letter will come to your future self through your email address. You can choose to receive your letter in six months, a year, five years, or ten years.
I just sent myself a letter to receive in 5 years. Due to my bad memory, I assume that by the time my letter comes back to me, it will catch me off guard as a pleasant surprise.