Free SPF Checker
Look up the SPF record for any domain and see exactly which servers are authorized to send email as that domain — with every mechanism explained in plain English.
No account needed. Domains are used for the lookup and never stored.
What SPF is and how receivers use it
Sender Policy Framework is the DNS record that tells the world which servers may send email using your domain.
What is SPF?
SPF is a single TXT record published at your domain that lists the mail servers allowed to send on its behalf. When a receiving server accepts a message, it compares the connecting IP against that list. A match is an SPF pass; anything else is handled according to your all policy.
How the check works
The receiver takes the domain in the SMTP envelope sender, queries its TXT records, and evaluates mechanisms left to right: ip4, ip6, a, mx, include and finally all. The first match wins, so the trailing all only applies to senders nothing else matched.
Fixing common problems
Two SPF records? Merge them into one. Over 10 lookups? Remove unused includes or ask providers for IP ranges. +all published? Replace it with ~all immediately. Missing a provider? Add their documented include before the all mechanism, never after it.
A worked example
v=spf1 include:_spf.google.com ip4:198.51.100.10 ~all authorizes every Google Workspace server, plus one specific IP address, and asks receivers to treat all other senders with suspicion. That is a healthy record for a Gmail-based sender with one extra relay.
Check your email authentication
SPF is one of three records receivers look at. Run all three checks to see the full picture: SPF authorizes servers, DKIM signs your messages, and DMARC tells receivers what to do when either one fails.
Frequently asked questions
Everything people usually ask about this tool.
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