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.f1lby commented
Which is why we are abandoning O365 for spam filtering and commencing the implementation of a non Microsoft spam filtering solution.
As of today ( 17 Sep 2019) I have seen 23 (very obvious) phishing emails from other O365 tenants which Microsoft have allowed through.
I do diligently report EVERY SINGLE instance, but never see any change or get a response from Microsoft.
I'm extremely disappointed in the inability of Microsoft to take this situation seriously. My 'home grown' transport rules are far more effective than what Microsoft can offer in identifying spam!
Sorry Microsoft, but I've been waiting 18 months for you to wake up, but you're asleep at the wheel, while your customers are deluged with criminals knocking on their doors.