1234, West 67 Street
Carlisle, MA 01741
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
Dear Chris klinton,
I cannot express just how much the recommendation of my catering service has meant to me. Sarah Lamb has put in an order and I think that it could lead to a lot more work for me. The recommendation you gave to your friends has helped my business to grow and I cannot thank you enough for that.