Write a letter expressing thanks, and deliver it in person. The Riverside Church in the City of New York.We are an interdenominational, interracial, international, open, welcoming, and affirming church and congregation. For a professional letter, use a more formal closing like "Sincerely" or "Respectfully. Learn how to write an employee appreciation letter with these templates and examples. Download the template for free (PDF or Word). Upload your Statement of Purpose, Personal History, and Writing Sample PDFs. The message of appreciation should stand alone. Be brief, warm, and sincere. Beyond a professional and courteous 'Thank you for your offer, which I am pleased to accept', there is no need for anything else.