Note: SendLater is no longer for sale. Its functionality is now included in Feigeist's MailButler, whose link can be found int he following paragraph.
SendLater--which is now a part of MailButler, the complete assistant for Apple Mail--gives you the ability to send email at a specific date and time in the future. Normally, emails are immediately sent to the recipient when you press Mail's "Send" button, but SendLater provides a new button to work its magic. This allows better control of your emails and is more than handy in the following situations: