Dear Mr./Mrs. XYZ,
It is glad to say that, the (date…) can mark your tenth anniversary being a member of the (name of company..), We would like to take this opportunity to thank you for these memorable of past ten years connected with fine workmanship and organization loyalty.
We know that the growth and success of our company is largely dependent on having strong and capable staff members, such as yourself, and recognize the contribution you make in helping us maintain the position we enjoy in the industry.
We are hoping that you will remain with us for many years to come and want to offer our congratulations with this anniversary.
Designation with signature…