Microsoft Office 2003 - Use Do Not Deliver Before To Postpone The Sending Of A Message (Outlook 2003)
Often it happens that you have information (and inclination) enough to draft a letter, but don't need to send it just yet. Now Outlook allows you to control exactly when you send out a given message. This may be especially helpful around holidays or when you go on vacation.
To postpone sending your message, compose your note, and then click the Options button above the To text box. In the Message Options dialog box, select the Do Not Deliver Before check box, then select a date and time from the dropdown boxes next to the check box. Click Close and send the message. The message is saved in the Outbox until it's time to send it, and waiting messages will be sent at the specified time even if Outlook isn't running at the moment.