SenderCheck: Find out why your email lands in spam, and the exact fix

Hi Product Hunt, I'm Minh and I built SenderCheck. Most email checkers tell you something is "failing" and leave you to work out what that means. I wanted one that shows its working. For every problem it quotes the exact DNS record it read, says what is wrong in plain English, and gives you the change to make, written for your provider when it can tell (Google Workspace, Microsoft 365, Zoho and others). Why it matters: we ran SenderCheck over 1,362 US marketing agencies and IT firms, the companies other businesses trust with their email, and 1 in 4 publish no DMARC record at all. The full write-up is at sendercheck.net/research/agency-email-authentication Four things I was strict about: - It won't guess. If it can't tell which services send mail as you, it shows the shape of the SPF record instead of one to paste. A wrong include quietly breaks real mail. - It says what it can't know. A DNS check can't tell you whether one particular message will reach an inbox, and there is a page listing exactly what SenderCheck does not claim: sendercheck.net/docs/what-we-do-not-claim - The checker is free with no account. Paste a domain, an email address or a URL and you get the full report. - Sender reports are free too, on every plan. They take one DNS edit to point your DMARC reports at us, and the first report usually arrives within a day. After that you get a plain list of every service sending email as your domain, with the date each one first appeared: sendercheck.net/sender-reports If you want it watched, paid plans re-check your domains every day or more often and email you when a problem appears, gets worse, or gets fixed, with a history of which record changed and when. The Agency plan covers 100 client domains with white-label reports for $299 a month, published, no sales call. One question for you: what's the email problem you've spent the longest debugging? I'm using the answers to decide what to check next.