SharePoint IRM question regarding "Users must verify their credentials using this interval"

https://support.office.com/en-gb/article/Apply-Information-Rights-Management-to-a-list-or-library-3bdb5c4e-94fc-4741-b02f-4e7cc3c54aa1

In the above article it mentions:

• Helps to prevent an unauthorized viewer from viewing the content if it is sent in e-mail after it is downloaded from the server

• Restricts access to content to a specified period of time, after which users must confirm their credentials and download the content again

So unauthorised users still cannot view the document.