The following is what I would like to be added as a feature for Google Admins:

There was an internal email from my organizations Human Resources department that was sent to the entire company with a red banner indicating it was potential spam. The option to mark as “Looks Safe” was displayed to view the contents on the email.

There should be a way for Admins to mark internal emails as safe on post delivery. As of right now, the Investigation tool only allows us to classify as spam, phishing, etc. 

This would be the other way around and could help organizations from high spam score/classifications from within the company.