You can delay the delivery of an individual message or you can use rules to delay the delivery of all messages by having them held in the Outbox for a specified time after you click Send. This can be especially handy for managing communication across different time zones, working outside of business hours, or simply planning your correspondence in advance. Here's a step-by-step guide to help you set up a delayed email in Outlook.
For New Outlook
While composing a message, select the dropdown next to the Send button and select Schedule send.
Choose a custom time and then select Send.
After you select Send, the message remains in the Draft folder until the delivery time.
For Classic Outlook
While composing a message, select the More options arrow from the Tags group in the Ribbon.
Under Delivery options, select the Do not deliver before check box, and then choose the delivery date and time you want.
Click Close.
When you're done composing your email message, select Send.
After you click Send, the message remains in the Outbox folder until the delivery time.