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SIMPLE SYSTEMS / E-MAIL TOOLS
Inspect public DNS for a commercial Microsoft 365 / Exchange Online setup.
Copy these from the Microsoft 365 admin center or Defender portal. Exact values are tenant-specific.
Queries are sent through this website to Google Public DNS. Checks cover MX, SPF, Autodiscover, both DKIM selectors, the domain’s DMARC record and the optional Microsoft verification TXT record. Gateways, hybrid deployments and sovereign clouds may need different records. Public DNS cannot confirm tenant ownership, DKIM signing being enabled, or successful mail delivery.
Reference: Microsoft 365 DNS records · Microsoft DKIM setup
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