Dear …
I want to take this opportunity to express to you my deepest gratitude for all the time you’ve given me over the past __(length of time)__. I feel very fortunate to have had you as my mentor, coaching me on so many levels.
There’s so much I have learned from you; both on a technical level and about myself. Not only have you taught me a great deal about __(the world of business/finance/etc.)__, but through your support and encouragement, I’ve also learned to believe that I am capable of so much more than I ever thought I could be. Now, that’s truly the essence of a great coach and for that I can’t thank you enough.
You really are a wonderful mentor, __(Name)__, always accessible and willing to help. I can’t tell you how much I appreciate the enormous part you played in helping me to __(reach new heights in my career/grow into a new position at …./etc.)__. The impression you’ve left on me has me hoping to be able to emulate you one day.
Thanks again.
Sincerely,