Open Outlook and go to the Sent Items folder
Double-click the email you want to recall
Select File
Select Info
Select Resend or Recall
Select Recall This Message
Choose Delete unread copies of this message or Delete unread copies and replace with a new message
Optionally select Tell me if recall succeeds or fails for each recipient
Select OK
If replacing the message, edit the email and send it again
Check the recall status notification from Outlook if available