Subject: Farewell and Thank You!

Dear [Employee's Name],

As you prepare to leave [Company Name], we want to take a moment to express our heartfelt appreciation for your contributions during your time with us. Your dedication, hard work, and positive attitude have made a significant impact on our team and the organization as a whole.

We are especially grateful for [specific qualities or contributions, e.g., your leadership on the recent project, your ability to mentor new team members, etc.]. Your efforts have not gone unnoticed, and you will be greatly missed.

While we are sad to see you go, we wish you all the best in your future endeavors. Please keep in touch, and remember that you will always be a part of the [Company Name] family.

Thank you once again for everything!

Warm regards,

[Your Name]
[Your Position]
[Company Name]
[Contact Information]