456, X Street, Y Avenue,
[Subject: Normally bold, summarizes the intention of the letter] -Optional-
Dear Andrew Hall,
I am extending my sincerest appreciation for your heartfelt service on your employment’s twelfth year anniversary here at Zen Corporation.
Zen Corporation hired you by reason of your impressive academic performance and your many abilities. I am a witness to your effective and efficient work performance and I believe that you are a very valuable employee here at Zen for your hard work even during difficult times. I am grateful for your efforts.
Congratulations on your twelfth anniversary and may your success continue throughout all the years.