Name of the department
Dear Mr. / Miss (Name of the person)
I, on behalf of (department name), appreciate you and your team on the efforts and sincerity in successfully handling the presentation was pleased to see the team accomplish the goals. I personally thank you for assisting the team and achieving the goals. It was concluded successfully with your help.
We sincerely appreciate your role in the success and hope that you will keep up the good work in the future also.
On behalf of the management we want you to know that we really value your dedication towards work. Thank you for giving this company your best.
With best wishes,
(Name of the person sending the letter)