A complete notary acknowledgment includes the date the document was signed in front of the notary. The DBH PIO shall issue a detailed letter acknowledging and thanking the donor for the gift, as the donor may need for tax purposes.What do you need to include in your donation acknowledgment letter? Toll Free Number: 1.888.4.GOODWILL. A donation acknowledgment letter (sometimes called a donation receipt or thankyou letter) is an email or paper that recognizes a charitable contribution. Acknowledging Your Donation.