Defaults.Exposed › Stats › Email authentication (SPF, DKIM, DMARC)
What percent of domains publish MX records?
October 2026 census edition
As of October 12, 2026, 54.3% of the domains graded in the Defaults.Exposed census publish explicit MX (Mail Exchange) records: 180,564,746 domains set up to receive email. The grading engine's own mx-record check, a separate pass from the one behind this count, counts 180,462,439 (54.3%), the figure on the methodology page.
MX record adoption: how it is measured
It comes from the mail-routing pass, which reads each domain’s MX records and attributes them to the managed provider behind the hostnames, or records them as self-hosted when no provider matches. Every domain in the census is measured directly and counted once.
Publishing MX records is the signal that a domain expects to receive mail. It is measured here mostly as a denominator: many email statistics only make sense against mail-receiving domains rather than against every registered name, and this is the figure that separates the two.
Because the figure is a share, the denominator carries the weight: it is the set of domains where this check had something to read. A domain the census could not decide on is recorded as undetermined and left out, never counted as a failure.
It moves when domain owners publish, correct or remove the DNS (Domain Name System) records that authenticate their mail. Every one of those records is free and takes minutes to publish, and together they decide whether someone else can send mail as the domain. The number is recomputed from the raw evidence at every edition. What it cannot tell you is where one particular domain stands: for that, see fix your email authentication.
the full grading methodology · the underlying dataset, published open with the counts behind every percentage. If a figure here disagrees with one elsewhere on the site, the dataset is canonical and we would like to know.
MX record adoption: how to cite it
Please cite Defaults.Exposed and link this page. The citation below carries the date.
Defaults.Exposed, "What percent of domains publish MX records?" (as of October 12, 2026). https://defaults.exposed/stats/what-percent-of-domains-have-mx-records
Permalink: https://defaults.exposed/stats/what-percent-of-domains-have-mx-records · Machine-readable: /stats/s/mx-adoption.json · Licence: open data
Methodology: how we grade the internet · Source data: census data and downloads. Updated with each census edition.