Revising email can definitely lead to better communication, but how do you develop the revision habit? My own solution is pretty simple: compose important mails in a word processor rather than in the email software itself.
Sending off emails in a hurry can lead to some pretty embarrassing gaffes, as Lifehacker readers revealed yesterday. But even if you don't make a career-limiting move by sending off an email too hastily, you can often compromise effective communication by not reworking your original thoughts. Revising an email 50 times, as suggested by blogger David Silverman, seems a tad extreme to me, but I'm definitely down with the principle. My longstanding habit when composing important emails (work pitches, tricky questions for interview subjects, delicate family communications) has been to assemble that document in Word, and only send it off after it's been properly revised.
Given that my preferred email client has long been Outlook, which includes Word's editing features built in, that might seem a tad perverse. But for me, Word (running full-screen, a useful tactic when concentrating on writing) is just the natural place to craft and revise text. I've also got a decades-old habit of reflexively typing Ctrl-S to save documents, which is a bit risky in Outlook, where Alt-S will send the message in question. And having to select, copy and paste the finished result into an email (I started this practice before Word had a Send option on its File menu) means that I'm less likely to send something off before it's properly done.
It's not a necessary tactic for brief emails -- indeed, I'm also a fan of the EOM marker for much email communication -- but when important information needs to be conveyed, it's worth the extra effort.