How Do I get into that section of the settings where I can unban the users etc as my emails keep bouncing ?

Hi Michalis Fotis

If your emails are bouncing because Microsoft has restricted the account from sending mail, the area you may be looking for is the Restricted users page in the Microsoft Defender portal. When a user exceeds outbound sending limits or is flagged for suspected spam activity, Microsoft can place the account on this list, which prevents it from sending email.

If you are a Microsoft 365 administrator, you can check:

• Sign in to the Microsoft Defender portal: Microsoft Defender
• Go to Email & collaboration > Review > Restricted users
  • Or open: Restricted entities - Microsoft Defender
• If the affected account appears there, select it and choose Unblock.

If you do not see the account listed, please share the exact bounce message or NDR (for example, any error code such as 550 5.1.8 or 550 5.7.703). Different bounce errors can indicate different causes, such as a restricted sender, a blocked domain/address in the Tenant Allow/Block List, or another mail flow issue.

And I hope you understand that as forum moderators, we do not have access to your tenant or Microsoft's internal systems, so we cannot view or remove restrictions directly. We provide only technical guidance and best-practice recommendations based on reported issues.

I look forward to your response.

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