惠书

惠书	huì shū	(formal) your letter
惠	Huì	surname Hui
惠	huì	(bound form) act of kindness (from a superior) / (honorific prefix) kind (as in 惠顾)
书	Shū	abbr. for 书经
书	shū	book / letter / document / CL:本,册,部 / to write