Someone is threatening to sue me (they are currently unaware that have concrete evidence proving I wasn't responsible for what they say I am). I received a letter from their lawyer in which they state, quite categorically, that I am responsible. Obviously this is untrue and so would constitute libel, but I am unsure as to whether the fact that the letter was addressed soley to me affects this status?
I suppose I'm asking does written slander (Libel) have to be openly published?