What do you need to include in your donation acknowledgment letter? A donation acknowledgment letter (sometimes called a donation receipt or thankyou letter) is an email or paper that recognizes a charitable contribution.A classic donation letter contains a summary of your story, your core messages, and how you are addressing the issues you face. Find free donation acknowledgement letter templates in Word and PDF format that you can use to seek donations. Your recent contribution demonstrates how concerned individuals can make the difference in providing our patients with superior care well into.