About MailSetupCheck and its author
Who builds MailSetupCheck, the credentials behind it, how the site is funded, and how to report a wrong result, a changed rule or a wrong price.
The author
MailSetupCheck is built and maintained by one person, a Principal ML engineer, who publishes under the site's name.
- 10+ years in machine learning, from research to production
- Former Staff ML Engineer working on document extraction and OCR
- Former Lead ML Platform Engineer for a 5,000-stream computer-vision platform
- Contributor to vLLM; creator of Videoflow (1,000+ GitHub stars)
Why this site
I am a software engineer, not an email-deliverability consultant, and I built MailSetupCheck the way I would build any system I have to trust: from the specifications. Every rule in the checker comes from an RFC or from Gmail's, Yahoo's or Microsoft's own published requirements, each one is linked from the result it produces, and the code that applies them is tested against real DNS answers before every change goes live.
Most small businesses learn about SPF, DKIM and DMARC when their invoices start landing in spam. The records are short, but the rules behind them are spread across a dozen standards and three mailbox providers' help pages, and most checkers stop at "fail" without saying what to type into the DNS settings. MailSetupCheck tries to close that gap: what is wrong, why it matters, how urgent it is, and the exact record to add.
How the site is funded
The checker and the calculator are free and need no account. The site may earn referral or affiliate commissions from some vendors it mentions, such as cold-email tools. Every such link is labeled "(paid link)" where it appears, and none is active today, so every vendor link is a plain link. The affiliate disclosure lists every relationship. There is no advertising and no sponsored content.
Independence
MailSetupCheck is not affiliated with Google, Yahoo, Microsoft, any email provider, or any email tool. Vendors cannot pay to change a finding, a tier, or their place in the calculator's table. The site publishes no reviews or testimonials.
Corrections
Email hello@mailsetupcheck.com to report a wrong result, a rule that has changed, or a price that is out of date. Please include the domain you checked only if you are comfortable sharing it. Corrections are dated on the page they affect.
Also available as Markdown.