Subject
Thank you, [donor's first name]
Dear [donor's first name],
Thank you for your gift of [amount] to [your organization] on [date of gift]. It is your first, and we noticed.
Here is what it does: [what the gift makes possible]. That is not a figure of speech. It happens because you chose to give.
We will write now and then to show you what your support is doing. If you ever have a question, just reply to this letter; a real person reads every one.
With gratitude,
[your name] [your title] [your organization]