piece of correspondence (incl. email)
Han Xin (-196 BC), famous general of first Han emperor Liu Bang 劉邦|刘邦[Liu2 Bang1]
the Xin dynasty (8-23 AD) of Wang Mang 王莽, forming the interregnum between the former and later Han
lit. cut sleeve (idiom); fig. euphemism for homosexuality, originating from History of Western Han 漢書|汉书: emperor Han Aidi (real name Liu Xin) was in bed with his lover Dong Xian, and had to attend a court audience that morning. Not wishing to awaken Dong Xian, who was sleeping with his head resting on the emperor's long robe sleeve, Aidi used a knife to cut off the lower half of his sleeve.
lit. raised up by Xiao He, cast down by Xiao He (idiom), alluding to Han Xin 韓信|韩信[Han2 Xin4] being made Grand General 大將軍|大将军[da4 jiang1 jun1]
fig. a situation where one's success and failure are both due to the same factor