Resignation letters are a record that should be provided pursuant to a FOIL request.
Below are two opinions from the Committee on Open Government, which are on point.
https://docs.dos.ny.gov/coog/ftext/f8158.htm
“… the three page letter of resignation
constituted a “record” subject to the Freedom of Information Law.”
“The letter of resignation was given to Town officials in their
capacities as Town officials. To suggest that it is not a record
subject to the Freedom of Information Law would in my opinion
clearly conflict with the interpretation of that statute by the
State’s highest court.”
While government officials have privacy rights, they have less of a privacy right than the general public.
https://docs.dos.ny.gov/coog/ftext/f18099.html
“It is clear that public officers and employees enjoy a lesser degree of privacy than others, for it has been found in various contexts that those persons are required to be more accountable than others.”
Below are some recent news articles that mention a resignation letter being released through a FOIl request.
https://www.allotsego.com/foil-request-results-demystify-supers-abrupt-resignation/
Otsego School Supt
https://www.muckrock.com/foi/grand-island-23117/maria-burns-resignation-letter-145287/
Grand Island Court
https://www.muckrock.com/foi/cattaraugus-22339/elizabeth-n-ensells-resignation-letter-former-assistant-district-attorney-133706/
Cattaraugus County DA