Sealed with a Kiss (movie, 1999)

Bennett, who's engaged to his boss's daughter, just lost a major client for his company. When a letter meant for someone else is accidentally mailed to his home, Bennett tries to return it to its author. She turns out to be Robbie, curator of the museum home of the poet Longfellow which is desperate for funding. Bennett is drawn to Robbie and decides to help her save the museum. In the process, he finds himself reevaluating his life.