Use the tool, don't abuse the tool. That's most of it, but here's the specific version, since "don't abuse it" doesn't hold up in a dispute.
WTFSPF resolves a domain's public DNS records, its SPF record and related records like DMARC, follows the SPF record's includes, counts DNS lookups against the RFC 7208 limit, and explains what it finds in plain English. It's a free diagnostic tool. It is not a guarantee that your email will deliver, that a receiving server will interpret your record the same way we do, or that nothing else is wrong with your domain's email setup.
The service is provided "as is," without warranty of any kind. We resolve real DNS at the moment you ask, and DNS changes, propagates unevenly, and occasionally times out; a report reflects what we saw, not an eternal truth. Before you rely on a finding for something that matters, verify it against RFC 7208 and your own testing.
Check domains you have a legitimate reason to check. Don't script requests to hammer the checker, try to route other traffic through our DNS resolution, or otherwise try to break or overload the service. We rate-limit checks per IP address and may throttle or block traffic that looks abusive, no advance notice required.
This is a free tool run alongside our other products, not a paid service with an uptime commitment. We may change, add to, or discontinue any part of it, including specific findings or the report format, without notice.
To the extent the law allows it, we're not liable for damages arising from your use of, or inability to use, WTFSPF, including email that didn't deliver, decisions made based on a report, or downtime.
The WTFSPF name and mark, and the site's design and text, belong to us. The DNS records we analyze belong to whoever published them, not to us. The report we generate is yours to use, share, and copy into a ticket for whoever needs to fix the record.
We'll update this page if the terms change, and adjust the date below. Continuing to use WTFSPF after a change means you accept the new terms.
Questions about any of this: hello@wtfspf.com.
Last updated 2026-08-19.
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