email-transport · severity low
Mail server reverse DNS
Share of mail servers with no reverse-DNS (PTR) record — a common, quiet cause of degraded deliverability.
Measured every Friday · last updated
How it is measured
Tier 0. Resolve the MX, then PTR on the reversed address (bounded DNS query). Denominator: has_mx.
Why it matters
Missing reverse DNS is a classic quiet failure — nothing breaks visibly, but receiving mail systems downgrade or reject on it, so outbound deliverability degrades in ways that surface as "our email sometimes doesn't arrive".
The base rate
Two independent populations. The global, domain-anchored figure is unbiased; the company-anchored figures are built by matching company names to domains and skew toward more digitally-mature firms. Both are published, so the gap is visible.
By company size band
Company-anchored cuts (national registries with a size proxy), split by size band. Right-hand figure is the share not meeting the control.
Every segment
Pick one to see the citable answer for a company like yours, with its trend and methodology.
Show the remaining 5 segments
Slices below 100 measured members are withheld rather than shown with a wide interval — an absent country or issuer means too little data, not zero failures. Licensed CC BY 4.0. Machine-readable data per segment: append .json or .csv to its URL.