Out going Email services for our domain are currently not functioning

Question

Team,  

Please fix the issue , i am not using any bulk email still my outgoing has stopped . my business and client interaction has stopped .Please fix urgently 

[Moderator note: personal info removed] 

Regards,

[Moderator note: personal info removed] 

Answer 1

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.  

Hi @Purchase

Thank you for sharing your concerns. 

First, I’d like to clarify that this is a user‑to‑user support forum. Moderators participating here do not have access to backend systems, nor can we directly intervene in Microsoft product functionality. Our role is limited to providing technical guidance and sharing best‑practice recommendations based on reported issues, requests, and scenarios.      

Additionally, I will place your information in Private Message to ensure your privacy and security. This helps protect your personal information and prevents any sensitive details from being exposed publicly. To view or send private messages, please sign in to the Microsoft Q&A forum using the account that created this thread, then select Private Messages.  

As your description, the error message: "550 5.7.705 Service unavailable. Access denied, tenant has exceeded threshold" this indicates that your Microsoft 365 / Exchange Online Protection has temporarily blocked outbound email sending at the tenant level. This is a security measure triggered when Microsoft detects a high volume of messages or suspicious sending activity. As a result, your entire Microsoft 365 tenant is currently restricted from sending emails to external recipients. 

You could ask your current administrator to investigate and respond to any potentially compromised email accounts, enable multi-factor authentication for Microsoft 365, and configure the tenant with enhanced security settings.

For further information, you can refer via: NDR error codes 550 5.7.703, 550 5.7.705, 550 5.7.708, and 550 5.7.750 - Microsoft Support 

To troubleshoot this,  Microsoft’s support team will need to step in. A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.  

Reference: Get support - Microsoft 365 admin | Microsoft Learn 

Note: To create a support ticket, you need to have Microsoft 365 admin privileges and if you aren’t admin of your organization, please contact the admin of creating a new ticket. 

If you have any additional concerns, feel free to comment below. I would be more than happy to assist. 

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