This is so close to the old movie A letter to three wives
A Letter to Three Wives is a 1949 American romantic drama film which tells the story of a woman who mails a letter to three women, telling them she has left town with the husband of one of them. It stars Jeanne Crain, Linda Darnell, Ann Sothern, Paul Douglas in his film debut, Kirk Douglas, Jeffrey Lynn, and Thelma Ritter. An uncredited Celeste Holm provides the voice of Addie Ross, the unseen woman who wrote the titular letter.
A Letter to Three Wives is a 1949 American romantic drama film which tells the story of a woman who mails a letter to three women, telling them she has left town with the husband of one of them. It stars Jeanne Crain, Linda Darnell, Ann Sothern, Paul Douglas in his film debut, Kirk Douglas, Jeffrey Lynn, and Thelma Ritter. An uncredited Celeste Holm provides the voice of Addie Ross, the unseen woman who wrote the titular letter.