Delay Email Sending With Outlook

Less known Outlook feature is an ability to delay email sending. When you compose your email message, just go to Options tab > More Options group > and click Delay Delivery.

Note that this only works if Outlook is open during the time that the message should be sent. Otherwise, it might not be sent.

A more convenient way of scheduling email is using ScheduledSend - Email Scheduler for Microsoft Outlook.