Gmail users can help protect sensitive information from unauthorized access using Gmail confidential mode.
You can send messages and attachments with Gmail's confidential mode to help protect sensitive information from unauthorized access. You can use confidential mode to set an expiration date for messages or revoke access at any time. Recipients of the confidential message will have options to forward, copy, print, and download disabled.
How Gmail processes confidential mode messages
When someone sends a confidential mode message, Gmail removes the message body and any attachments from the recipient's copy of the message. These are replaced with a link to the content. Gmail clients make the linked content appear as if it's part of the message. Third-party mail clients display a link in place of the content.
Confidential mode messages and Vault
Vault can hold, retain, search, and export all confidential mode messages sent by users in the student.utwente.nl domain. Vault has no visibility into the content of confidential mode messages sent to you from external parties.
More information can be found on the Google support website.
Note: This only applies to students. They are using a G Suite environment where Gmail is activated.