SPF (Sender Policy Framework) is a TXT record that lists the mail servers authorized to send email for a domain. Receiving servers check SPF to reject or flag forged senders.

What is the difference between -all and ~all?

-all (hard fail) tells receivers to reject email from unauthorized senders. ~all (soft fail) marks suspicious email but usually still delivers it. -all is more secure once you are sure all legitimate senders are listed.

DMARC builds on SPF and DKIM and tells receivers what to do when authentication fails. The policy (p) can be none (monitor only), quarantine (send to spam), or reject (block).

Where does the DMARC record live?

DMARC is published as a TXT record at the _dmarc subdomain, for example _dmarc.example.com. It must start with v=DMARC1.

sigxlabs/Network Tools

SPF / DMARC Checker

Check SPF, DMARC, and MX records for any domain. Validate email authentication setup.

spf checker

spf record checker

dmarc lookup

mx record finder

Domain name

How to use

1
Enter a domain
Type any domain name like example.com. The protocol and www prefix are removed automatically.
2
Click Check
We query the TXT records for the domain and its _dmarc subdomain via DNS-over-HTTPS.
3
Review SPF
See the SPF record, its mechanisms (include, a, mx, ip4, ip6), and the final -all or ~all policy.
4
Review DMARC
See the DMARC record tags including the policy (p=none, quarantine, or reject).

FAQ

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