Epistle from landlord? (6)
I believe this clue is a double definition.
'epistle' is the first definition.
(I've seen this before)
'landlord?' is the second definition.
(landlords let property)
'from' is the link.
(Other definitions for letter that I've seen before include "Item sent - character", "It's one of twenty-six", "Alphabetic symbol", "A written form of communication", "who may offer terms to residents?".)