Le Corbeau (1943) on Netflix

A French village doctor becomes the target of poison-pen letters sent to village leaders, accusing him of affairs and practicing abortion.

A vicious series of poison-pen letters spreads rumours, suspicion and fear among the inhabitants of a small French town, and one after another, they turn on each other as their hidden secrets are unveiled - but the one secret that no-one can uncover is the identity of the letters' author...

—Michael Brooke <michael@everyman.demon.co.uk>

In the village of Saint Robin, the population receives anonymous letters signed as The Raven spreading rumors and accusations. Dr. Rémy Germain, who is having an affair with Laura, the wife of the psychiatrist Dr. Vorzet that works with him at the local hospital, is the main victim of The Raven. His affair is disclosed and he is also accused of abortionist. When a patient of the hospital commits suicide after receiving a letter telling that his cancer is terminal, the loathed nurse Marie Corbin is arrested since people believe she is The Raven. But soon there are other letters and Dr. Vorzet tries to identify who might be the notorious Raven.

—Claudio Carvalho, Rio de Janeiro, Brazil