DMARC check
See whether a domain has DMARC and which policy it uses against spoofed mail.
About DMARC check
What it is
DMARC builds on top of SPF and DKIM and tells receiving servers what to do with mail that fails the checks, and it sends reports back to you about who is mailing in your name.
Why it matters
DMARC is what actually stops forged mail. Without an enforced policy (quarantine or reject), scam emails using your address can still get through, even if you have SPF and DKIM.
Tips
- Start with p=none to see reports without blocking anything.
- Move up to p=quarantine and then p=reject once the reports look clean.
- Add a rua address so you receive aggregate reports to follow up on.
Common questions
What is the difference between p=none, quarantine and reject?
none only monitors, quarantine moves forged mail to the junk folder, and reject blocks it entirely. reject is the strongest.
Do I need SPF and DKIM for DMARC to work?
Yes, DMARC relies on the results from SPF and DKIM, so both should be in place first.
More lookups
MX lookup
See which servers receive mail for a domain, and which provider handles it.
SPF check
Check whether a domain has an SPF record and how strictly it rejects spoofed mail.
DKIM check
Look for DKIM signing on a domain using the most common selectors.
DNSSEC check
See whether a domain is protected with DNSSEC, that is, whether its DNS answers are signed.
TXT lookup
List all TXT records for a domain, including SPF, verifications and more.
NS lookup
See which name servers control a domain's DNS.
Blacklist check
Check whether a domain's IP address is on blacklists such as Spamhaus, Barracuda and SpamCop.
A/AAAA lookup
See which IP addresses a domain points to, both IPv4 (A) and IPv6 (AAAA).
CNAME lookup
See whether a domain is an alias that points on to another domain.
SOA lookup
See the zone's core data: primary name server, contact and serial number.
CAA lookup
See which certificate authorities are allowed to issue certificates for the domain.
Reverse DNS (PTR)
Look up which host name a domain's IP address points back to.
MTA-STS
See whether a domain requires encrypted mail delivery via MTA-STS.
TLS-RPT
See whether a domain receives reports about failed encrypted mail delivery.
BIMI
See whether a domain publishes a logo that can be shown in the recipient's inbox.
SSL certificate
Check a domain's TLS certificate: issuer, validity and expiry.
Whois
See who owns a domain, when it was registered and when it expires.
HTTP security headers
Check whether a domain's website sets important security headers.