Please tweak a letter to include the specifics for your company.
From attcnetwork.org --
Acceptance letter: Resignation
This morning, regretfully, I received your letter of intent to resign from your position as administrative assistant. I accept your resignation and appreciate your giving me sufficient notice and time to find a competent replacement.
In addition to having an exceptional attendance record, an excellent work ethic, and an enviable talent to write well, you have been a loyal friend. Finding someone to fill your shoes will be no easy task. Nevertheless, I wish you all the best in your future endeavors. You deserve it.
We are genuinely sorry to receive your letter of resignation informing us of your departure on June 5. We will miss you very much. We have enjoyed working with you and have come to depend on your competent assistance. Good counselors are hard to find, so keep us in mind if your new position does not turn out as you expect.
I am sorry to hear that you are leaving the organization. I understand that your last day is Friday, November 5. The departure of an excellent employee is always a bittersweet event. You will be missed, but we all hope the best for you. Your contributions to product development, particularly to the motivational incentive program, were superlative. I wish you continued success in your new job. Please keep in touch.
From insiderreports.com --
It is with deep regret, that we accept your resignation
As [job title/position] of the [organization].
We can appreciate the demands that this position has placed
On you, and appreciate all of the fine contributions you
Have made as [job title/position].
We wish you all the best in your new endeavors.
Yours very truly,