HCW8092 One or more items failed validation during 'Configure Mail Flow' task

Question

Answer 1

My MX record points to the gateway, and then the next one is mapped to the firewall for the local Exchange. Ports 25 and 443 of the Exchange are both mapped to the firewall, and I've checked that the ports are functioning correctly. When configuring the hybrid environment, I tried using the FQDN pointing to both the local server and the gateway, but I encountered the same error issue. I really can't figure out what else could be affecting my mail flow.

Answer 2

Hello, @Duebass

Welcome to the Microsoft Q&A platform!

Based on your description, you have already done a lot of troubleshooting. Here are a few additional steps you might consider:

1.Firewall and Network Configuration: Double-check that all necessary firewall rules are in place and that there are no network issues. Ensure that the firewall allows traffic from Exchange Online IP addresses and URLs.

2.TLS Configuration: Verify that the TLS settings on your Exchange server are correctly configured. Sometimes, issues with TLS certificates or settings can cause validation failures.

3.Hybrid Configuration Wizard (HCW) Logs: Review the HCW logs for more detailed error messages. These logs can provide specific information about what might be causing the validation to fail.

4.Email Gateway: Since you're using an email gateway, ensure that it is not interfering with the mail flow. Sometimes, security appliances can block or alter the traffic in unexpected ways.

5.DNS Records: Ensure that all DNS records, including MX, SPF, and Autodiscover, are correctly configured and pointing to the right locations.

6.Exchange Connectors: Check the connectors in both Exchange Online and on-premises Exchange to ensure they are correctly set up and not causing any issues.

7.Service Connectivity: Check the connectivity between Office 365 and on-premises server using tools like the Remote Connectivity Analyzer (https://testconnectivity.microsoft.com/).

Hope the troubleshooting above can help you to find what could be affecting your mail flow. If you need further help, please feel free to reply this post directly so we will be notified to follow it up.

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Thank you for your support and understanding.

Best Wishes,

Alex Zhang

Answer 3

I've seen a similar question on Bing, though it's been a long time, but according to the client, do you really need to point MX records to the local Exchange Server?

https://learn.microsoft.com/en-us/answers/questions/942317/hcw8092-one-or-more-items-failed-validation-during

Does anyone know why it is?