[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 you today to ______________________ [reason for writing-express my appreciation for something, convey appreciation to someone, etc.]. This ___________________ [any event associated with the appreciation, such as a special appreciation party] on __________________________ [date of appreciation party, etc.].
Please ___________________ [action item-RSVP by a certain date, including contact information, etc.]. Again, I want to express my most sincere appreciation.
[Sender's first and last names]