This article explains how to schedule an email in Outlook so that you can write it now, but have it sent at a date and time that you specify. Instructions apply to the desktop version of Outlook 2010 and later.
Outlook – Three Ways to Send Later – Delay Delivery, Schedule Send, Viva Insights
Microsoft Outlook lets you schedule email messages to be sent at a later time, instead of sending them immediately.
Compose your message as you normally would, whether it's a new email, a reply, or a forward. Then go to the Options tab and select Delay Delivery (it's nested in the three-dot menu in some versions of Outlook).
Select the box next to Do not deliver earlier.
