Open Outlook and go to your Inbox or the folder where you want to send the email
Create a new email (or open a draft)
Enter the recipient(s), subject, and message content
Click the Options tab
Select Delay Delivery
Check the box next to Do not deliver before
Choose the date and time you want the email to be sent
Click Close
Click Send (the email will remain scheduled until the delivery time)
To view or change scheduled emails: go to Drafts (or Outbox, depending on your Outlook version)
Open the scheduled email to edit and reschedule, then click Send again
To cancel a scheduled email: open it from Drafts/Outbox and remove the scheduled delivery, then delete it