The purpose of letters of acknowledgment is to provide proof that you have received specific documents or a specific type of request. Thank you for sending me the (invoice, report, etc.).I can acknowledge that I have received it. Learn what an acknowledgement receipt is and how to create one for your business (with a template and two examples). I am writing to confirm my acceptance of your employment offer on April 20 and to tell you how delighted I am to be joining XYZ Corporation in Chicago. Learn how to use an effective letter of appreciation to show your gratitude for job opportunities, job search referrals, and other kindnesses.