No Emails Going Out - 5.7.705 Service unavailable. Access denied, tenant has exceeded threshold

Hi @Gavin Baijnauth

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.

It seems that you’re unable to raise a support ticket from the Microsoft 365 Admin Center. One possible reason is that your domain (or tenant) may still be federated with a provider (such as GoDaddy), which can limit or redirect support capabilities. In this setup, the provider often manages the support relationship with Microsoft, so direct ticket creation from the Admin Center may not be available.

In that case, you may need to contact GoDaddy support and ask them to open a support request with Microsoft on your behalf.

Before reaching out, it would be helpful to collect the following information to speed up the investigation:

As states in this documentthe error “550 5.7.705 Access denied, tenant has exceeded threshold” indicates that your organization sends too much spam or bulk mail, Exchange Online blocks your outgoing mail and generates this NDR. Either of these common scenarios can cause spam or bulk mail to pass through your organization:

• A compromised on-premises server that routes mail to Exchange Online
• A compromised admin account that's used to create connectors

In this situation, only an email admin in your organization can fix this issue.

If you're an email admin, please proceed to collect necessary information to make this process quicker when collaborating with Microsoft Support Team.

1.Go to Exchange Admin Center > Report > Mail flow > Top domain mailflow report Please check if you could find the compromised user as it should display in this mailflow report if the compromised user has been used to send out abnormal number of outbound emails.

2.Once you have the information of the compromised user, please proceed to go to Mail flow > Message Trace (within Exchange Admin Center). Furthermore, start a message trace up to 48-72 hours before the block happened (acknowledge from step 1 above).

Given an hour of waiting, please proceed to download the message trace as a *.csv file, which could be used to provide information to Microsoft Support Team later. (*The user *****@domain.com is an illustration for UPN of compromised user, please replace it with the result when you check it from Step 1)

3.Go to Connector section in Exchange Admin Center, check if there is any suspicious connector created then proceed to check and delete the suspicious connector. 4.Go to Rules section in Exchange Admin Center, check there is any suspicious rule created proceed to delete those rules.

5.Attempt to change the password of compromised user and also enforce MFA via this link:

After you have addressed the underlying cause, you will need to contact GoDaddy and request that they raise a support ticket with Microsoft on your behalf to remove the outbound sending block.

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.