Outlook blocks the wrong incoming messages

Question

Outlook blocks the wrong incoming messages. Sender gets a failure message "message blocked because its content is identified as spam". I need to cancel this restriction so such emails land in Junk, not get blocked and bounce back to sender. I checked all the related Junk settings, I'm already using Standard, not Strict protection. I don't have any rules to block such senders (mainly company domains). I'm a freelancer and can get an email from any potential/past client who is not in my contacts. So, making a list of safe senders won't be a practical solution. Any other ideas on how to fix this issue?

Answer 1

Hi engy bendary

Based on your description, it sounds like the messages are being classified as a more severe threat category (such as high-confidence spam or phishing) and therefore rejected before delivery, rather than being sent to Junk Email. Standard protection normally delivers regular spam to the Junk folder.

I recommend checking Message Trace for a blocked email to see the exact verdict and reason code. That will help determine whether the rejection is caused by anti-spam policies, anti-phishing protection, or another mail flow rule. (Message trace in the new EAC in Exchange Online | Microsoft Learn)

If this is a personal Microsoft account (outlook.com) rather than a Microsoft 365 business account (account provided by your organization), there are no advanced spam policy settings available to change how Microsoft's backend filtering handles these messages.

If possible, could you share the full Non-Delivery Report (NDR) or bounce-back message received by the sender (with any personal information removed)? The exact error code and rejection reason would help determine why the messages are being blocked instead of being delivered to Junk Email.

---

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.