Dear _________,
It is with a great feeling of nostalgia that I write to you at this time. Because of various personal issues, it has become necessary for me to take an early retirement. It is with great joy that I will reminisce about all of the times we pooled our talents together to rise up and meet a new challenge and emerge victorious! And how can I forget all of the late night and weekend brainstorming sessions with cold pizza and bad Chinese take-out. Our marketing firm has seen a lot of changes both industry wide and in the advancement of technology. We’ve accomplished so much together, we have a lot to be proud of. Thank you for your kindness, loyalty, and professionalism. I will miss you all.
Sincerely,
(YOUR NAME HERE)