Dear Mr Watson, I am writing to you to congratulate you on the efforts that you did to make the yearly executive conference successful. Getting the responsibility of an event manager was a milestone in your career.
Dear Mr William, I am writing to you to congratulate you for making the annual executive conference successful, which was organized on 23rd November 2021. Everything went well by dint of your hard work and effective planning.
Dear Jeremy, Hope you are doing excellent. I am writing this letter to congratulate you on organizing this year's annual executive conference quite successfully.