mail shot
n.— «Supposing that I decided to rent the mailing lists of other people and send those potential customers a letter (usually referred to as a ‘mail shot’), I might reasonably get between 1% and 2% of those people to buy from me.» —“How to manage win-win-win situations using Joint Ventures” Best-of-the-Internet Website Traffic Resources May 7, 2006. (source: Double-Tongued Dictionary)