We use in-place holds to ensure emails deleted in error (by mistake or intentionally) are recoverable. While this should prevent a user from permanently deleting an email, there should be a way for admins to completely delete emails including from Recoverable Items (particularly Purges, Versions and DiscoveryHolds) without affecting the remainder of the hold.

Perhaps something like Search-Mailbox -DeleteContent -RemoveFromRecoverableItems

This is particularly relevant to exercising a data subject's right to be forgotten under GDPR.