Email Auth Checker
What to provide first
Domain
Enter only the root domain like example.com. If the email address is support@example.com, you should check example.com, not the full email address.
DKIM selector
This is optional. If your email service gave you a DNS host like default._domainkey.example.com, the selector is default. If you do not know it, leave it blank and still check MX, SPF, and DMARC.
Need help finding it?
You can usually find the sending domain and selector in your email provider dashboard, DNS panel, or the message details from our Email Header Analyzer.
This tool checks the DNS records that support deliverability and sender trust. For suspicious incoming messages, use the Email Header Analyzer or Email Spam Checker too.
What this tool does
It checks whether a domain has working MX, SPF, and DMARC records, and it can also look up an optional DKIM selector. This is useful when you are setting up business mail, improving inbox delivery, or checking why emails fail authentication.