[Your letterhead, if desired; if not, your return address]
[Date of letter-month, day, and year]
[Recipient's first and last names]
[Street or P.O. box address]
[City, State ZIP code]
Dear [recipient's name]:
I am writing to thank you for ______________________ [reason for writing-mention who you are thanking, what you are thanking him or her (or them) for, any other specifics, etc.]. This ____________________________________ [mention any additional and pertinent details about the issue].
Please ___________________ [any action items regarding the issue-contact me, etc.]. Thank you again for your generosity and thoughtfulness, and [any additional details].
[Sender's first and last names]