DNS is not working

Question

Hello

Please i need your help on this issue.

One of my customer is having an issue where DNS is not working.

We need assistance with their emails working and DNS

Answer 1

Hello, @John Peter,

Welcome to the Microsoft Q&A platform!

DNS issues can disrupt email functionality when records like MX, SPF, DKIM, and DMARC are incorrect, outdated, or misconfigured. Incorrect MX records, for instance, can misguide email routing, while issues such as propagation delays, server outages, or stale cache data can further complicate resolution. Ensuring these records are accurate and current is essential for maintaining reliable email delivery.

To pinpoint the root of the problem, start by verifying your DNS records with tools such as nslookup or online DNS checkers. Check that your MX record and any related A or CNAME records are correctly configured. Additionally, clear the DNS cache on affected systems (using commands like ipconfig /flushdns on Windows) to eliminate issues caused by outdated local cache entries. This process can help determine whether propagation delays or cache problems are affecting email functionality.

Finally, review your email server’s configuration along with the SPF, DKIM, and DMARC records to ensure secure and proper email delivery. Confirm that your DNS servers are operational and consider temporarily switching to reliable public DNS servers—like Google DNS (8.8.8.8 and 8.8.4.4)—to see if resolution improves.

Official Reference Documents:

1.Troubleshooting DNS Servers | Microsoft Learn

2.Find and fix issues after adding your domain or DNS records - Microsoft 365 admin | Microsoft Learn

Should you need more help on this, you can feel free to post back. 

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Best Wishes,

Alex Zhang