I stumbled upon this on the internet as I tried to write the politest rejection letter ever:
Herbert A. Millington Chair - Search Committee
412A Clarkson Hall, Whitson University
College Hill, MA 34109
Dear Professor Millington, Thank you for your letter of March 16. After careful consideration, I
regret to inform you that I am unable to accept your refusal to offer me
an assistant professor position in your department.
This year I have been particularly fortunate in receiving an unusually
large number of rejection letters. With such a varied and promising field
of candidates, it is impossible for me to accept all refusals.
Despite Whitson's outstanding qualifications and previous experience in
rejecting applicants, I find that your rejection does not meet my needs at
this time. Therefore, I will assume the position of assistant professor
in your department this August. I look forward to seeing you then.
Best of luck in rejecting future applicants. Sincerely, Chris L. J