A change due in December will improve how Exchange Online Protection suppresses high confidence phish messages and stop them being delivered to user mailboxes. The old-fashioned allowed sender and allowed domain lists are being taken out of the equation and ignored when EOP is sure that it’s dealing with some high-confidence phish. It’s time to check your anti-spam policies.
https://office365itpros.com/2020/11/19/improve-exchange-online-protection-anti-phish/
