Vault Usage for Confidential Messages in Gmail
The Confidential Mode in Gmail Beta Programme coming into play with Vault adds an extra layer of security.

You would be wondering what confidential messages in Gmail are all about. Let’s quench the thirst in this article.
…….Gmail confidential mode allows the users to restrict the recipients' access to sensitive email content for security and keeping things confidential. This feature is available to G Suite domains through Gmail’s confidential Beta program.
The messages sent via Confidential Mode can also be locked with a password which is sent via SMS messaging if the sender opts for it, or via email if the recipient is not using the Gmail app.
The expiration date of the emails sent via Confidential mode can be set by the sender which allows the deletion of the emails after a certain period of time and ranges from one day to five years. If it is required to remove all traces of the mails then it must be deleted from the sent folder as well.
Now you must know what Google Vault is….
Google Vault is a place that lets you hold, retain, search, and export data to support an organization's archiving and eDiscovery needs. Email messages, Google Groups, Files in Google Drive and Team Drives are supported by Google Vault. Vault allows archiving corporate data from G Suite products like Gmail, Google Drive and Google Teams.
The confidential messages are always available in the Google Vault, even if the sender sets an expiration date or withdraws recipients' access to the confidential messages. The users may receive confidential mode messages from outside parties such as other G Suite customers or from personal Gmail accounts. The message headers and the subjects of external confidential messages can be held, retained, searched and exported. However, message content or attachments from outside confidential messages cannot be searched or exported. Admins only will be affected by this new feature introduced in Google vault and no end users will have any knowledge of it.
This launch adds support for new data types so that the organisations using G Suite can comprehensively govern their paramount data.