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Glossary

SPF

SPF (Sender Policy Framework) is a DNS record in which a domain lists the mail servers allowed to send email for it.

Updated · By Otman Ounana · How we research

Why it matters when you send from your own Gmail

A receiving server checks the server that delivered a message against that list. Google says messages that fail its authentication checks might be marked as spam or rejected with a 5.7.26 error.[1] If you send from a personal @gmail.com address, Google publishes the record for you and there is nothing to set up. If you send from your own domain on Google Workspace, the record on that domain has to name Google's servers, and it is worth checking before the first email goes out, because a missing record is invisible until mail starts landing in spam.

Example

For a domain on Google Workspace the record usually reads v=spf1 include:_spf.google.com ~all. It says that Google's servers may send for the domain, and that anything else should be treated with suspicion.

What to do

Send yourself a test message and open its original headers in Gmail. The line Authentication-Results shows whether SPF passed. If it did not, fix the record before you send to anyone else.

Related terms

All terms are on the glossary.

Read next

  • Gmail 550 5.7.1 errorsGmail's 550 5.7.1 bounce has more than a dozen meanings. The ones a person sending from their own mailbox meets, quoted from Google's error list, with the fix for each.
  • The 5,000-a-day bulk sender ruleWho Google counts as a bulk sender, what counts toward 5,000, why it is permanent, and the arithmetic for someone sending cold email from their own mailbox.
  • DMARC checkerFree DMARC, SPF and DKIM checker. Enter a domain to see each record explained in plain words: policy, reports, SPF lookups and what to fix. Runs in your browser.
  • Postmaster ToolsPostmaster Tools is a free Google service that shows a domain's owner how Gmail sees the mail it sends, including the rate at which recipients mark it as spam.

Sources

  1. Google, Email sender guidelines. “Messages that aren’t authenticated with these methods might be marked as spam or rejected with a 5.7.26 error.” Read on 1 October 2026.