Re-opening a closed lead? What to write in the e-mail

Products develop, market situations keep changing and people change their minds. This is why it is recommended, after some time, to re-approach prospects who have previously rejected you, especially if you felt during the first unsuccessful round there was a possibility the given prospect would decide differently in the future.

But what should an e-mail reminding the prospect of the existence of your product look like? Here are some tips.