Explanation:
See Subunit 1.2. In Chapter 5 of 'Time Management for Creative People', Mark McGuinness cites Mark Forster's advice for dealing with the "never-ending stream of e-mails." Forster's book 'Do It Tomorrow' advises that you move yesterday's e-mails into a folder marked "action." These are the only e-mails you will be dealing with that day.