123 Cherry Street
Any City, Any State, XXXXX
Month, day, year
Dear Personnel Director (or Manager, Owner, etc.):
It is with great sadness that I am hereby tendering my resignation.
I believe that you know my reasons for making this decision; therefore, I will not mention the specific issues. If you wish to discuss the reasons, I would be willing to meet with you privately.
I have appreciated the opportunity to work for the XYZ Corporation for so many years. I offer my best wishes for its continued success.