SPF

SPF generator and checker

Q: ~all or -all — which one?

~all softly flags a message as suspicious; -all rejects it outright. People usually start with ~all until they’re sure every legitimate sender is listed.

SPF states which servers are allowed to send mail on behalf of your domain. Build a record or check an existing one.

Build a record

Extra addresses (ip4:)

Space- or comma-separated, if mail is also sent by your own server.

What to do with the rest

@TXTv=spf1 include:_spf.google.com ~all

1 of 10 DNS lookups

The 10-DNS-lookup limit

Every include is a separate DNS lookup, and the spec allows no more than 10 for the whole chain. Exceed it, and SPF fails for every message, with no visible warning to the owner.

Check a domain

Frequently asked

I have two SPF records — is that a problem?

Yes. A domain can only have one SPF record; two records are treated as a misconfiguration and can fail the check.

~all or -all — which one?

~all softly flags a message as suspicious; -all rejects it outright. People usually start with ~all until they’re sure every legitimate sender is listed.