Inboxproof runs a real deliverability audit on your domain: MX, SPF, DKIM, DMARC, TLS and IP reputation. It hands you a score, the exact records to fix, and daily monitoring. No setup. No XML forwarding. No sales call.
Prefer a checklist? Free 12-point email deliverability checklist
Just want a quick look? Free email spam checker · Free DMARC checker · SPF checker · DKIM checker · IP blocklist checker · MX record checker · email header analyzer · DMARC report parser · cold email deliverability checker · email warm-up calculator · TLS/STARTTLS checker · reverse DNS (PTR) checker · need the record itself? DMARC record generator · SPF record generator. No email needed. · comparing tools? best deliverability tools · Mail-Tester alternatives · GlockApps alternatives
We query live DNS for MX, SPF, DKIM, DMARC, TLS and IP reputation. No account, no DNS changes, nothing to install.
A 0–100 deliverability score with every check itemized. Each failure comes with the exact TXT record to paste into your DNS.
Pro re-runs the full audit every 24 hours and alerts you the moment a record breaks, expires, or a provider changes your sending IP.
No marketing score. Every check is a live lookup against your DNS and your mail servers, run the same way inbox providers do.
Valid MX records, resolvable targets, no CNAME loops, correct priority ordering. If mail can't route, nothing else matters.
Present, syntactically valid, under the 10-lookup limit, and ending in -all so receivers reject spoofed senders.
We scan 50+ common selectors (google, selector1, s1, mandrill, sendgrid, amazonses…). Key found? We check it's 1024-bit or stronger.
The big one for 2026. We verify the record exists, parses, and enforces (p=quarantine or reject), not just p=none on paper.
We open a real SMTP connection to your MX, negotiate STARTTLS, and validate the certificate chain and expiry.
Your sending IPs checked against Spamhaus, SpamCop and Barracuda lists. One bad IP and every message you send gets flagged.
Mail servers increasingly reject hosts without a clean PTR record matching the sending hostname.
Every audit is stored. Watch your score climb as you fix records, and catch regressions the day they happen.
Pro domains are re-audited daily. The moment SPF breaks or a cert expires, you get the email, not your customers.
The free audit is the real product, not a teaser. Pro adds the monitoring that keeps it true.
Launch offer: 50% off your first month, applied automatically at checkout. Cancel anytime from your dashboard, no lock-in. Backed by a 30-day money-back guarantee.
Every check is a live lookup, weighted by how much it affects real inbox placement. Pass = full weight, warning = half, fail = zero. The same method runs on the free audit and on Pro monitoring.
DMARC and MX carry the most weight because they decide delivery first. A domain can't score well by fixing only the easy checks.
Each audit queries your DNS and opens a real SMTP connection to your MX. What you see is what a receiver sees right now.
Every failure comes with the record to add or change: the host, the type, and the value. No "consider improving your SPF".
We never write to your DNS, your mailbox, or your ESP. The audit is the same read-only lookups Gmail and Microsoft run.
No. The audit is read-only: we query your public DNS and talk to your mail servers the same way Gmail and Microsoft do. To fix issues, we hand you the exact records to add. You or your DNS provider applies them.
Three things converged: inbox providers (starting with Gmail) now hard-enforce DMARC, AI agents generate and read a huge share of business email, and AI spam is sophisticated enough to pass human review but fail authentication. Domains that can't prove identity get filtered before a human ever sees them.
Point checkers test one message or one record. Inboxproof scores the whole domain across seven live checks, weights them the way receivers do, stores every result as history, and on Pro re-runs everything daily so you find out when something breaks, not when your customers stop replying.
Your address is used to save your audit history and, if you start Pro, to deliver daily monitoring alerts. We don't sell data or send marketing. Delete your data any time.
Each check has a weight reflecting how much it affects real inbox placement (DMARC and MX carry the most). Pass = full weight, warning = half, fail = zero. 90+ is inbox-ready, 70+ is good, 50+ is at risk, below that your mail is likely being filtered.
Short, practical explainers. No fluff, no fake stats. Every claim is something you can verify with a DNS lookup.
What p=none actually does, alignment, and the safe order to go from monitoring to enforcement.
What each record proves, what breaks when one is missing, and the exact TXT to start from.
The three lookups that answer it in 30 seconds, and what to do if the answer is yes.
The complete 2026 checklist: SPF, DKIM, DMARC, and the other records you need to get into the inbox.
Why Gmail rejects your email with this error, and how to fix it by configuring SPF, DKIM, and DMARC correctly.
Why your DKIM signature might not be working, and how to fix it.
A practical comparison of the main tools, and the deliverability layer that decides whether any of them land in the inbox.
The stack that keeps every client inbox-ready: per-domain auth, daily monitoring, and white-label reports.
The order that matters: fix authentication, clear blocklists, correct the sending behavior, then monitor so it stays out.
Reply rate is decided before your first word of copy: by whether the email reaches the primary inbox.
What each metric means, how to read reputation, and what to do when a number moves the wrong way.
The DNS records to look up, what each result means, and the order to check them in.
The checks that matter, what is worth paying for, and how to avoid the marketing fluff.
What the code means, the three records to check, and the order to fix it.
The four causes in order of likelihood, and the exact check for each one.
What Yahoo checks, the records it requires, and the order to get out of spam.
What the code means, the five causes in order of likelihood, and the exact fix for each one.
The five causes in order of likelihood, the exact check for each one, and the fix that works.
The four causes in order of likelihood, and the exact check for each one.
What's a good number, why it matters, and how to bring a high bounce rate back under control.
Run the audit now. It's free, it's live, and it takes 30 seconds.
Run my free audit →Your audit is saved to . Get Pro and we'll re-run this audit daily and email you the moment anything breaks.