Forum Discussion

ALV_Work's avatar
ALV_Work
Copper Contributor
Apr 10, 2019

Outgoing emails marked as SPAM and Phishing emails by O365 servers

Hi, Since yesterday, all outgoing emails from our organization using Office365 (fully cloud) are being flagged as either spam or phishing email by Microsoft Outbound email servers. Due to this our...
exchange
office 365
  • Rafmoerkens's avatar
    Rafmoerkens
    Apr 12, 2019

    Philippe_RAYNAUD 

     

    You might want to read the following article on the "health" tab in the office portal...

     

Akshay_Mane's avatar
Akshay_Mane
Iron Contributor
Apr 10, 2019

ALV_Work  

This is the typical case of HRDP, when your outbound emails are detected as spam and EOP tries to deliver it to recipient with already blacklisted ip.

social.technet.microsoft. com/wiki/contents/articles/36402.exchange-online-troubleshooting-high-risk-delivery-pool.aspx
 
Looking at the headers, it seems that EOP IP 52.101.129.90 is on blacklist
Try to delist the IP on sender.office. com
 
Sometimes your tenant gets assigned a blacklisted IP in random. You can contact O365CloudExperts Support if you need more help.
 
Regards,
Akshay M

Resources