Free tool
SPF check.
Paste a domain. We'll find your SPF record, count DNS lookups, and show your include chain.
What is SPF?
SPF (Sender Policy Framework) is a DNS TXT record that lists which mail servers are allowed to send email on behalf of your domain. It's one of the three pillars of email authentication (alongside DKIM and DMARC).
Why it matters
Without SPF, anyone can send email that appears to come from your domain.
Mailbox providers use SPF to decide whether to trust incoming messages.
The 10-lookup limit
SPF allows a maximum of 10 DNS lookups per evaluation. Each
include:, a:, mx:, ptr:, exists:, and
redirect=
counts. Exceeding this causes a PermError — your SPF fails entirely.
What we recommend
Keep your SPF record simple. Use
include:
for each sending provider,
end with ~all
(softfail) or -all
(hardfail), and stay under 10 lookups.
Next tools
Also available: DKIM check, MX check.