This is one of those experiments that can blow your mind... years later. The idea behind the FutureMe.org platform is simple. All you need to do is write an email to yourself which will be delivered to your inbox years later.
Of course, if you don't want to wait for several decades to read what you wrote to yourself, you can choose to get the email in one, three or five years. Of course, you can also set a much later date, with the furthest one available being 2068.
You can also share your email with others by marking it “Public, but anonymous”, and the provider of this service obliges to use your email address solely for this purpose.