Error code 550 5.7.x in Microsoft Exchange

Issue symptoms
End users receive a bounce back notification from Microsoft after they send an email to a support address.
The notification starts with: Your message could not be delivered.
The message includes an error or status code with 550 5.7.x.
The emails don't reach Zendesk.
The text of the message will be different for each underlying issue. However, the main problem remains the same: the user's email was rejected before it could reach Zendesk. Resolution steps These errors are generated by Microsoft, not Zendesk. Zendesk cannot assist in resolving these errors. If your users suddenly report bounce back notifications and error messages, contact your email administrator. They will need to review the error message and your email configuration.
Note: This type of error can occur on a support address that previously worked. That typically means something has changed. For example, if Microsoft implements a new policy for email forwarding, previous addresses may not meet the new requirements without an update. The email administrator for your email domain can investigate and resolve these errors. Microsoft may have updated its policies around automatic email forwarding, and it may affect support addresses that synced in the past. For more information, see this article: Forwarding incoming email from your existing email address to Zendesk Support. Alternatively, you can connect your non-Zendesk email servers, based on Microsoft Exchange, to your Zendesk account with the latest Microsoft Exchange connector. For more information, see this article: Connecting your Microsoft Exchange account to Zendesk.
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What is the "550 5.7.x" error code? Why do end users or customers receive a "Your message could not be delivered" bounce back notification? Why do emails fail to reach Zendesk Support or your help desk?
This error indicates that Microsoft rejected the email from the requester or end user before it could reach Zendesk Support or your ticketing system. Microsoft generates these errors, which typically means something changed in your email configuration. This issue can occur on a support address that worked in the past if Microsoft updates its policies to forward email automatically.

Can Zendesk fix the "550 5.7.x" error code? Does Zendesk Support or your help desk assist with these Microsoft Exchange errors?
No. Microsoft generates these errors, not Zendesk. Zendesk cannot assist you to resolve these errors. The email administrator or agent for your email domain must investigate and resolve the issue.

How do you fix the "550 5.7.x" error code? What steps resolve the "Your message could not be delivered" error for a support address?
You can resolve these errors if you perform one of the following actions:

Contact your email administrator to review the error message and your email configuration.
Connect your non-Zendesk email servers, based on Microsoft Exchange, to your Zendesk account with the latest Microsoft Exchange connector.


