About This Tool
The Mail Configuration Checker reviews public DNS records that are important for business email operation. Enter a domain name to retrieve MX records, identify whether SPF and DMARC are published, and estimate common services such as Google Workspace or Microsoft 365 from the MX host names. The A to D grade is designed as a quick operational check for troubleshooting delivery issues, preparing a server migration, or reviewing a new cloud mail deployment. DKIM uses provider-specific selector names, so it is shown as unverified rather than being treated as missing. DNS changes may take time to propagate, and the result is a snapshot of publicly visible records.
When This Tool Is Useful
- Mail is not arriving
- Checking SPF
- Checking DMARC
- Before a server migration
- Reviewing a Microsoft 365 deployment
How to Use
- Enter the domain used after the @ sign in your email address.
- Click “Check mail configuration.”
- Review the grade, mail service estimate, and individual DNS records.
FAQ
What is SPF?
SPF is a DNS-based policy that lists servers authorized to send mail for a domain.
What is DMARC?
DMARC tells receiving systems how to handle messages that fail SPF or DKIM alignment and can provide reports.
Why does legitimate mail go to spam?
Common causes include missing or incorrect SPF, DKIM, or DMARC records, poor sending reputation, message content, and recipient-side filtering.
Can it check Google Workspace?
Yes. Google Workspace can often be estimated from Google MX host names, and its SPF and DMARC records are checked.
Can it check Microsoft 365?
Yes. Microsoft 365 can often be estimated from mail.protection.outlook.com MX records.
Why is DKIM shown as unverified?
DKIM selector names differ by provider and organization, so a domain name alone is not enough for a reliable automatic check.
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