Look up and validate the SPF record of a domain, with its DNS lookup count.
The SPF record checker looks up the SPF TXT record of a domain, explains every mechanism in plain words and follows the includes to count the DNS lookups. More than 10 lookups, several SPF records or a +all at the end break SPF for every email.
SPF (Sender Policy Framework) lists the servers that may send email for your domain. With DKIM and DMARC it stops spoofing and helps your emails reach the inbox.
Follows includes and redirects, counts against the limit of 10.
What ip4, include, a, mx and all mean.
The SPF records of every included domain.
Multiple records, +all, ?all, ptr and void lookups.
A TXT record on the domain, e.g. v=spf1 include:_spf.google.com ~all.
SPF may trigger at most 10 DNS lookups (include, a, mx, ptr, exists, redirect). Above that, SPF returns a permanent error.
~all (soft fail) is safe while you set things up; -all (hard fail) is stricter. With DMARC, both work.