Learn how to write an employee appreciation letter with these templates and examples. Download the template for free (PDF or Word).Thank you very much. Guidelines for writing appreciation letters: State what you appreciate and briefly explain why. An employee appreciation or thank you letter is a formal message from an employer that recognizes the former's contribution to the company they work for. Once again, thank you for your unwavering support and encouragement. Your belief in me has made a profound difference in my life, and I am forever grateful. Sending out customer appreciation letters is an excellent way to connect with your clients. Learn how to write a customer appreciation letter here. We are immensely and sincerely appreciative for your contribution to our event!