My friend has the facility - in her employer's IT system - to withdraw, scrub, delete an email after it has been sent, resulting in its non-existence. I don't know how this works, but it saved her from much embarrassment once when she sent an email to the wrong person!
Some email providrs will also let you search for and restore deleted emails. Outlook for instance. Open the "Deleted Items" folder and look if there is a "recover items deleted" option. Have a look in there perhaps. You get 30 days after the email was deleted to use the facility. Again I am talking Outlook. (Hotmail in old money)
If you use eg, GMX mail collector to access your emails from a different email provider there is an option to "delete email from source" when you read it via GMX. I use this option to delete any emails sent to my btinternet.com mailbox but not those sent to my talktalk mailbox. If you are using a mail collection service make sure the option to delete is not set.