How To Write A Contest Winner Letter . Such a letter is a brief document that contains information of a commercial nature and covers one or more questions. This letter announces a good news in an upbeat tone. Image Gallery sweepstakes letter Sweepstakes, Online sweepstakes, Pch from www.pinterest.com The following is the email format that should be followed while writing a winner announcement letter. Begin the letter by announcing that the recipient. It also promotes goodwill in a group while focusing on a particular person.