ex-box
n.— «Ex-box n. hidden container of old love souvenirs.…An ex-box holds mementos of ex-lovers. It may be a physical container (of letters, photos); an electronic folder, disk or website (of old emails, jpegs, love-blogs); or a less tangible but equally emotional place in the mind.» —“What’s the word” by John Hind Guardian (U.K.) Aug. 14, 2005. (source: Double-Tongued Dictionary)