It's Sunset Again (1978)

It's Sunset Again 1978 / 又是黃昏 1978 / You shi huang hun , Oncemore in the Evening , Another Day, Another Evening!

When her boyfriend, Meng Hu, went abroad to pursue his study and had no news, Ling Na thought he had no longer loved her. She met him many years later by a chance encounter, but he was already a married man. After much clarifications, they realized that Ling’s mother had secretly intercepted all their earlier mails to stop their relationship.