425 votesin the plans · 19 comments · Office 365 Security & Compliance » Auditing · Flag idea as inappropriate… · Admin →
576 votes29 comments · Office 365 Security & Compliance » Spam & Phishing · Flag idea as inappropriate… · Admin →
ATP does not consider mails from other Office 365 tenants, or even mailboxes inside of your tenant, as safe. The best way to put a stop to this is to follow the recommendations in SecureScore for your tenant; and report phishing mails to us promptly. Also, make sure that the sender is not allowed either by the tenant configuration or the user safelist.Chris Hager commented
This is HUGE. The problem worsens the more people migrate to O365. We've performed a number of these migrations but are considering switching to G Suite because this has gotten so problematic for our clients.