The letter 'was couched in' polite terms.
a psychiatrist's 'couch'
(..) - I need to get her to sign something. - Yeah. Don't get on her nerves. How would I get on her nerves? Hello! Shouldn't I be on the couch? No, Maurice. Not today. I've got some good news. I think you've downed the corner. I'm not going on the couch? You don't need me any more, Moss. (..)2006 TvShow: The IT Crowd Title: Aunt Irma Visits Season: 1 Episode 6