Terms of Service

Last updated: September 2, 2026

These Terms of Service ("Terms") govern your use of DNSTrustCheck (dnstrustcheck.com, "this site", "the Service"), operated by Gary Thomas. By using this site, you agree to these Terms. If you don't agree, please don't use the Service.

The Service

DNSTrustCheck is a free tool that runs DNS, WHOIS, SMTP, and email-authentication lookups against a domain you provide, and against public infrastructure (nameservers, WHOIS registries, DNS blocklists) — the same kind of lookups your own computer could run directly. It also includes standalone generator and diagnostic utilities (SPF/DKIM/BIMI/MTA-STS builders, a DMARC report reader, header analyzer, and similar) and reference guides. No account or sign-up is required, and there is no paid tier; the site is supported by optional donations and, once you accept cookies, by Google AdSense.

Acceptable use

You agree to use the Service only for lawful purposes, and not to:

Attempt to disrupt, overload, or gain unauthorized access to the Service or the infrastructure it runs on, including bypassing rate limits, scraping the site at scale, or automating requests outside normal interactive use.

Use the Service to facilitate an attack against, or unauthorized reconnaissance of, a system you don't have the right to test — even though the checks themselves only query public, already-accessible DNS/WHOIS/blacklist data, you're responsible for how you use the results.

Upload or submit any file (including DMARC aggregate reports) or text (including email headers) that you don't have the right to share, or that contains malicious code.

We may rate-limit, block, or suspend access for any traffic that looks abusive, at our discretion, without notice.

What you submit

When you run a scan, paste email headers, or upload a DMARC aggregate report, that input is sent to our server to process your request. Domains and headers are used only to generate your result and aren't retained afterward; uploaded DMARC report files are parsed in memory and are never written to disk. See the Privacy Policy for the full breakdown of what's collected and why. You're responsible for making sure you have the right to submit whatever you paste or upload — for example, email headers or DMARC reports that reference other people's addresses.

Results are informational, not a guarantee

Scan results, health scores, and every check on this site are provided for informational purposes only and represent a best-effort snapshot at the time of the scan. They are not a certification, audit, or guarantee that a domain is secure, properly configured, or free of vulnerabilities, and a clean result does not mean nothing is wrong — see the notes on blacklist and subdomain-takeover check scope on the About page. DNS, WHOIS, and mail infrastructure can also change or be temporarily unreachable between one scan and the next, which can affect results. You're responsible for verifying anything security- or compliance-critical independently, and for consulting a qualified professional before making decisions based on these results.

Third-party services

The Service links to or relies on third parties for some functionality: Google AdSense (advertising, once you accept cookies), Stripe (for the optional donation link), and public DNS/WHOIS/DNSBL infrastructure operated by others. We don't control these third parties and aren't responsible for their content, availability, or their own terms and privacy practices, which govern your use of them directly.

Intellectual property

The DNSTrustCheck name, site design, and original written content are owned by the site operator. You may link to this site and reference or screenshot individual scan results (e.g., for your own records or to share with a client or colleague) without needing separate permission. Scan output about your own domain is yours to use as you see fit.

No warranty

The Service is provided "as is" and "as available," without warranties of any kind, express or implied, including any implied warranty of merchantability, fitness for a particular purpose, or non-infringement. We don't warrant that the Service will be uninterrupted, error-free, or that results will be accurate or complete.

Limitation of liability

To the fullest extent permitted by law, the site operator is not liable for any indirect, incidental, special, consequential, or punitive damages, or any loss of data, revenue, or business, arising from your use of, or inability to use, the Service — including decisions made based on a scan result. This is a free tool provided without charge, and these Terms allocate that risk accordingly.

Changes to the Service

Checks, tools, and guides may be added, changed, or removed at any time as the site evolves. We'll try to keep the site available, but don't guarantee uninterrupted access.

Changes to these Terms

These Terms may be updated from time to time as the Service changes. The "last updated" date above reflects the most recent revision; continuing to use the Service after a change means you accept the updated Terms.

Governing law

These Terms are governed by the laws applicable to the site operator's place of business, without regard to conflict-of-law principles, except where local law requires otherwise for consumer protection.

Contact

Questions about these Terms can be sent to [email protected].