How to reply a resignation letter?
As your manager has accepted the resignation,
here is a sample letter,
Dear X,
It is with deep regret that I accept your notice of resignation as [insert job title] with the organisation.
I appreciate your excellent contribution as [insert job title] to the team and the organisation for the past six years and am sorry to see you go.
I understand your decision to move on and have forwarded your letter of resignation to the Human Resources Department and Accounts Department who will contact you with further information on the procedures related to your departure.
I will organise a meeting tomorrow to discuss your handover of roles and responsibilities for a smooth transition leading to your last day on [insert last day of employment].
Thank you again for your commitment and dedication as [insert job title]. I wish you every success in your future undertakings and hope that you will keep in touch.
Yours sincerely,
[Insert manager’s name and job title]
Learning English by Uncle Teng 
