A manual DMARC check of your sending domain's email authentication — done by me, not a script. Free, by email, within 48 hours.
Not just "pass", but whether the domain that passed is actually your From domain. That gap is the single most common thing I find in audits — and Google's green checkmarks won't warn you about it.
Spamhaus and other major DNSBLs, for your domain and your visible sending infrastructure.
What's broken (if anything), why it matters, and the first fix I'd make. Plain English from a person — not a tool export.
Email ohmysendcom@gmail.com with the subject "Free Domain Check" and:
I do these by hand, in batches — expect a reply within 48 hours.
No card. No form. No signup.
It checks the authentication layer — the part that's either right or wrong. It won't tell you your inbox placement or your domain reputation trend; that needs Postmaster access and sending history, which is what the paid diagnostic is for.
If the check finds signs of something deeper, I'll say so. That's as far as the pitch goes.