"The email's different, I might have got it wrong"

The door is one kind of check. The email is another, and it deserves its own chapter, because the argument for it sounds stronger. A locked door is locked or it isn't. An email might contain a mistake, a wrong figure, a name misspelt, a tone that reads badly. Reading it again might really find something. So the sent folder is a different case.

I'd grant part of that and then look at the rest. Reading an email before you send it is the once. It's exactly the check this book defends. You wrote it, you read it through, you fixed the comma, you sent it. The question is what the reading after sending is for.

It can't change anything. The email has gone. Whatever it contains, the client has it. So the reread isn't a check in the sense of a chance to put something right. It's a search for a reason to feel bad or good about something that's over, and it will find one, because any piece of writing read with a suspicious eye has something in it. The comma that might have been a full stop. A sentence that could be read two ways if you tried. The third reading finds these because it's looking for them, and having found them it feels worse, not better, and there's nothing to be done, so you read a fourth time to see whether it's really that bad.

This is the fade from chapter 3, applied to a piece of writing instead of a door. The first time you read the email, you read what it said. By the third, you're reading your own doubt about it, and the words have gone flat and strange the way any sentence does when you stare at it. You can't tell any more whether the tone is fine, because you've lost the ability to read it as the client will, which is once, quickly, on the way to something else.

What follows is my own suggestion. Do the reading before sending, and do it properly, with the attention chapter 17 describes. Read it once for the facts and figures. Read it once for the tone, aloud if you can, as the person receiving it. Fix what needs fixing. Send. Then the sent folder is closed, and if the doubt arrives at eleven, it's the same doubt as the one at the lights, and it gets the same answer. The email was read, twice, by a careful person, and that's the once.

If something in it really was wrong, you'll find out the way everyone does, which is that someone tells you, and you send a correction, and the world goes on. That happens to everyone occasionally and it isn't prevented by the fourth reading. It's prevented, as far as it can be, by the reading before, and the reading before is the only one that can act.