I audit websites from the outside and then write to whoever owns them, which means I spend a lot of time in other people's contact channels — forms, chat widgets, published addresses. Over one week that came to seventy-odd contact pages and around a hundred messages. The thing I did not expect to learn: whether a message arrives is a completely separate question from whether the form works. Four failure modes, all measured, all of them holes that a site owner cannot see from the inside,...