DeliveryRadar watches your domain’s SPF, DKIM, DMARC, and TLS-RPT setup every day and emails you the moment something breaks: a new source failing, a record someone quietly changed, weak enforcement nobody caught. Built by a 2-person IT shop that found its own email authentication silently broken for months — these are the same checks we built to protect ourselves. Free instant scanner (no signup), or continuous monitoring with trend tracking and sender lookup for $19/mo.

Hey Product Hunt 👋

I’m Rajesh — I run CheckSumTek, a 2-person IT consulting shop. We’ve spent over a decade doing enterprise dev and architecture work, mostly for government/compliance-heavy clients, which means paying very close attention to things other people don’t think about until they break.

A few weeks ago I checked our own domain’s SPF and DMARC — just a routine look — and found both had been quietly misconfigured for months. Nothing was broken exactly: mail still went out, still landed. But our DMARC policy was sitting in monitor-only mode, meaning a clearly spoofed email pretending to be us would still get delivered, and our SPF was soft-fail instead of hard-fail. On top of that, one of our two mail systems wasn’t signing outbound mail with DKIM at all.

None of that shows up as an error. It shows up as degraded trust with Gmail/Outlook’s spam filters, and as phishing-as-you being easier than it should be.

We fixed it in about twenty minutes once we knew what to look for — and then built DeliveryRadar so we (and anyone else) would catch it the moment it happens again, not months later:

Free scanner, no signup: checks any domain’s SPF/DKIM/DMARC and tells you in plain English what’s wrong and what to fix
Daily monitoring ($19/mo or $180/yr): re-checks everything daily, plus TLS-RPT (SMTP TLS reporting), email alerts the moment a new source starts failing, a 30-day pass/fail trend chart, and reverse-DNS lookup so a raw sending IP becomes a readable hostname

It’s live, it’s self-serve, and it’s the thing I wish had existed when I was first untangling our own setup.

Would genuinely love feedback — especially from anyone who’s dealt with the “why did my open rates just drop for no reason” problem, since that’s usually this exact issue in disguise.

If anyone wants to try it on their own domain, the free scanner takes about 5 seconds and needs no signup: checksumtech.com/Tools/EmailCheck. I'm curious what it turns up — DMARC sitting in "monitor-only" mode (p=none) is shockingly common even on domains where someone thinks it's "set up," since it doesn't actually block anything in that mode. Happy to help read the results if anything looks confusing.