While there is technically no way to unsend an email in Outlook, emails can be recalled. This can be done using the "Recall This Email" feature of Outlook. However, this option is only successful in certain circumstances and may not work for all users.
To recall a message that has been sent, Outlook users first need to find the message in the "Sent Items" folder. The user may open the message and navigate to the "Actions" option. Once there users can find the "Recall This Message" option and select it. Users must also select the "Delete unread copies of this message," or the "Delete unread copies and replace with a new message" option if they want to send a new email. Users can also select an option to receive notifications regarding whether or not the recall is successful by selecting the option for "Tell me if recall succeeds or fails" for each recipient.
Recalling an email in Outlook is only successful if a recipient is not using Outlook, if a recipient is not logged on to the service provider for the email or if the recipient is working offline. If the original message has already been read or has been moved from the inbox, a recall cannot be performed.