Subscription blocked when using Azure Communicate service

Question

Dear teams,

I am using Azure Communication Service. But when I run test send email, I get this error:

""code":"SubscriptionBlocked","message":"All requests from this subscription are blocked due to the sender reputation that affects your delivery. Please reach out to Azure Support for further

What can I do to fix this error?

Answer 1

Hi @Pham Ngoc Trung ,

Thank you for sharing the additional information. Based on the details provided

The subscription was automatically blocked by Azure Communication Services Email due to a high email failure rate while using the Azure Managed Domain. To protect overall email deliverability, Azure enforces sending limits when delivery metrics exceed acceptable thresholds.

Resolution steps:

• Linked a Custom Domain to the Azure Communication Services Email resource
• Stopped using the Azure Managed Domain for outbound email
• Enabled email delivery logging to monitor failure rates
• Reduced and maintained the email failure rate below the required threshold
• Confirmed the subscription was in good billing standing

Once these conditions were met, the subscription block was lifted and email delivery was restored.

Best Practices:

• Use a Custom Domain for all production email sending
• Monitor email delivery logs and metrics regularly
• Keep failure rates within acceptable limits to avoid automatic blocking.

Please let us know if the above has been helpful to you or if you need additional assistance with this matter.

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Answer 2

The error message you are encountering indicates that your subscription has been blocked due to issues with sender reputation, which affects email delivery. To resolve this issue, you should take the following steps:

1. Monitor Your Sender Reputation: Ensure that your sender reputation is within acceptable limits. Azure Communication Services has specific requirements for sender reputation, and maintaining a low failure rate (less than 1%) is crucial.
2. Address Delivery Issues: Investigate and resolve any underlying issues that may be causing high failure rates. This includes checking for bounces, invalid email addresses, and ensuring that your email content complies with standards.
3. Contact Azure Support: Since the error message suggests reaching out to Azure Support, you should do so for assistance. They can provide specific insights into your account and help you understand the reasons for the block.
4. Gradual Increase in Email Volume: If you are trying to send a high volume of emails, consider gradually increasing your sending volume over a period of two to four weeks. This allows the email service to adapt and helps protect your sender reputation.

By following these steps, you can work towards resolving the subscription block and improving your sender reputation for future email deliveries.

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References:

• Service limits for Azure Communication Services
• Understand sender reputation in Azure Communication Services email