Does your newsletter not have valid unsubscribe links? Are your links in the email to log out and update settings invalid? This is due to the fact that in the preview of the emails the links to “Unsubscribe” and to “Update settings” are not displayed.
To test your “unsubscribe” and “update settings” URL, the easiest way to send the email is to use your test segment to test the links in the email.
How to create a Preference Center/Update Settings page for your emails and newsletters.