Why does my domain fail SPF when the record looks correct?

The two usual causes are both valid DNS. Having two SPF records on one domain is a permanent error and makes every check fail, even though each record is correct on its own. And an SPF record needing more than ten DNS lookups exceeds the limit and fails, which usually happens after adding one more include.

What DMARC policy do Gmail and Yahoo require?

A published DMARC record is required for bulk senders, and p=none satisfies it. You do not need enforcement to comply. Start at p=none, read the aggregate reports until your own mail is passing, then move to p=quarantine and p=reject.

What happens if I do not pass?

Since May 2026, Google and Microsoft reject bulk mail from a non-compliant domain with a permanent 550 rather than filing it in spam. The message is refused at the door, so there is no spam folder to check.

Free SPF, DKIM and DMARC checker

Since May 2026, Google and Microsoft reject bulk mail from a domain without SPF, DKIM and DMARC with a permanent failure rather than a spam folder. This checks all three and names what is wrong.

What this catches that a lookup does not

Most failures are valid DNS that is wrong for email, which is why checking that a record exists tells you almost nothing.

Two SPF records. Each one is correct on its own, and having both is a permanent error that makes every SPF check fail. This is the most common real misconfiguration and it is invisible unless you look for it.
More than ten DNS lookups in SPF. Over the limit the record fails, and it usually goes over the day somebody adds one more include.
A DMARC record with no p= policy. It resolves perfectly and receivers treat it as no DMARC at all.
An empty DKIM p= value. That is not a typo, it is how a key is revoked, and it means nothing you send is signed.
A DKIM key split by whitespace. Several DNS panels insert it into long values, and the key silently stops working.

The rules, in full

Anyone sending roughly 5,000 messages a day to personal Gmail accounts needs SPF, DKIM and DMARC passing, From-header alignment, valid forward and reverse DNS, TLS, RFC 5322 formatting, one-click unsubscribe headers under RFC 8058 with a visible link in the body as well, and a spam complaint rate under 0.30%. Google recommends staying under 0.10%; 0.30% is where enforcement begins, not a target.