In Claimable, if you delete an individual Message or an entire Conversation, any emails that have already been sent will remain available in the inboxes of the recipients, as it's not possible to delete an email after it has been sent.
If the email contains attachments, the download links will stop working shortly after Message deletion, although if the recipient has already downloaded an attachment it may remain on their computer or company network indefinitely.
Images embedded in the body of the email will remain visible even after the Message or Conversation is deleted in Claimable.