An email you previously had in Marketo under a program in Marketing Activities no longer exists and you believe it was deleted. However, you do not see that deletion in the Audit trail.
If an email was deleted directly, by un-approving the asset and then deleting it from the program, this activity will be seen in the Audit Trail.
However, if the program containing the email is deleted, the individual email's deletion will not show in the audit trail. Only the program deletion will be displayed.