Does Secure Email Threat Defense honor actions my users take on Junk mail in Outlook?
Users may mark email using the Outlook Junk options, such as Never Block Sender or Add to Safe Senders. If you want Secure Email Threat Defense to honor these settings, select the Do not remediate Microsoft Safe Sender messages with Spam or Graymail verdicts check box on the Policy page. Safe Sender flags are respected for Spam and Graymail verdicts, but are not respected for Threat verdicts. That is, Safe Sender messages with Spam or Graymail verdicts will not be remediated.