To recall and replace a message

  1. In the folder pane on the left of the Outlook window, choose the Sent Items folder
  2. Open the message that you want to recall. You must double-click to open the message. Selecting the message so it appears in the reading pane won't allow you to recall the message.
  3. From the Message tab, select Actions > Recall This Message.

  4. Click Delete unread copies of this message or Delete unread copies and replace with a new message, and then click OK.​

  5. If you’re sending a replacement message, compose the message, and then click Send.​

​https://support.office.com/en-us/article/recall-or-replace-an-email-message-that-you-sent-35027f88-d655-4554-b4f8-6c0729a723a0​