SPF check
Check whether a domain has an SPF record and how strictly it rejects spoofed mail.
About SPF check
What it is
SPF (Sender Policy Framework) is a DNS record that lists which servers are allowed to send mail in your domain's name. Receiving servers check the record to determine whether a message is genuine.
Why it matters
Without SPF, or with an overly permissive SPF, anyone can forge your sender address and send scam emails that appear to come from you. That harms both recipients and your reputation.
Tips
- End the record with -all for strict protection, ~all (soft) often lets suspicious mail through anyway.
- List every legitimate sender (your email provider, newsletter services, invoicing systems).
- Stay under ten DNS lookups in the record, otherwise SPF stops being evaluated.
Common questions
What does -all mean in an SPF record?
-all means that anything not explicitly listed should be rejected. It is the strictest and most secure setting.
Is SPF enough to protect against spoofing?
No. SPF should be combined with DKIM and DMARC for full protection against a forged sender.
More lookups
MX lookup
See which servers receive mail for a domain, and which provider handles it.
DMARC check
See whether a domain has DMARC and which policy it uses against 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.