SPF Checker

Find and validate a domain’s SPF record — including the all-important 10-DNS-lookup limit and the multiple-record trap that silently breaks SPF.

What SPF does

SPF (Sender Policy Framework) is a DNS TXT record listing which servers may send email as your domain. Receivers check it to help decide whether a message is legitimate or spoofed.

The two mistakes that break SPF

Two SPF records. RFC 7208 allows exactly one. A second record makes SPF PERMERROR — it fails for all your mail. Merge every source into one v=spf1 record.
Over 10 DNS lookups. Each include:, a, mx and redirect= costs a lookup; past ten, SPF errors out. Flatten or remove unused includes.

Related tools

DMARC Checker — the policy that acts on SPF/DKIM results.
MX Lookup — your mail servers.
Full DNS Lookup — everything at once.

Frequently asked questions

▸ Can I have more than one SPF record?

No — RFC 7208 allows exactly one per hostname. Two SPF records cause a PermError and SPF fails for all your mail. Merge them into one.

▸ What is the SPF 10-lookup limit?

SPF evaluation may perform at most 10 DNS lookups. Exceed it and SPF returns PermError and is ignored. Reduce includes or flatten to fixed IPs.