Muddiness is not merely a disturber of prose, it is also a destroyer of life, or hope: death on the highway caused by a badly worded road sign, heart-break among lovers caused by a misplaced phrase in a well-intentioned letter, anguish of a traveler expecting to be met at a railroad station and not being met because of a slipshod telegram.
– William Strunk and E.B. White, The Elements of Style
(I seem to use their quotes a lot – because they’re good! Although, I might change “telegram” in the one above to “email”!)