You can delete a sent message immediately after reading it or from the Outbox page.

  1. At the top of your dashboard, click the message icon to open the Inbox page.

  2. On the top right, click the Sent button to open the Outbox page. All sent messages will be displayed.

  3. Open the sent message you want to delete, and then click the Delete button.


           
                                                                                 Fig 1.

Or

  1. From the Outbox page, select the checkbox for the message you want to delete.


     

                                                                       Fig 2.

  1. Click the Delete button.


     

                                                                         Fig 3.

  1. Click OK to confirm.


For more information, watch this-