Email infrastructure changes slowly enough that nobody notices it changing at all. So we measured it. Using daily DNS snapshots from OpenINTEL (University of Twente), we reconstructed the mail stack of the Tranco top-1M domains across 192 monthly cuts, from January 2016 to the 2026-07-05 snapshot. As of that latest snapshot, 664,715 of those domains publish an MX record, 623,370 publish SPF, and 459,124 publish DMARC. Every number in this article comes from that dataset, and the underlying series update every day in our daily email infrastructure report.
Three stories dominate the decade: the slow death of the self-hosted mail server, the quiet unbundling of the ESP market, and an authentication layer that finally — partially — grew up.
The mailbox layer: a market cut in half
In January 2016, running your own mail server was still the default: 42.76% of top-1M domains with MX pointed at self-hosted infrastructure. By 2022 that was 30.18%. Today it is 22.53%. Meanwhile Google Workspace climbed from 15.4% to 21.75%, and Microsoft 365 nearly quadrupled from 4.46% to 16.68%.
The crossover dynamics matter more than the endpoints. Google's growth has flattened: +1.64 percentage points since 2022. Microsoft added +4.31 points over the same window — 2.6× faster. If the trend holds, the interesting question of the late 2020s is not "cloud vs self-hosted" but which of the two clouds consolidates the enterprise. Together they already hold 38.4% of every domain that can receive mail.
| Provider | 2016 | 2022 | 2026 |
|---|---|---|---|
| Self-hosted | 42.76% | 30.18% | 22.53% |
| Google Workspace | 15.4% | 20.11% | 21.75% |
| Microsoft 365 | 4.46% | 12.37% | 16.68% |
| GoDaddy mail | 4.23% | 1.49% | 0.75% |
Casualties and newcomers
Consolidation is not one story but a dozen smaller exits and entries happening at once:
- GoDaddy mail collapsed. The registrar-bundled mailbox went from 4.23% in 2016 to 1.49% in 2022 to 0.75% today — a slow-motion exodus toward Google, Microsoft, and forwarding services.
- Yandex 360 peaked in December 2019 at 5.56% and has since fallen roughly 70%, to 1.63%. Geopolitics is visible in MX records, months before it shows up anywhere else.
- Zoho Mail peaked at 1.68% in 2022 and drifted to 1.03%; SpamExperts fell from 0.99% to 0.41%.
- Security gateways grew against the tide. Proofpoint more than doubled from 0.86% to 1.91% since 2022, and Mimecast rose from 1.03% to 1.53% — the enterprise perimeter consolidating in front of the mailbox, not inside it. Amazon WorkMail also doubled, 0.34% to 0.71%.
- The fastest newcomer is free. Cloudflare Email Routing did not exist before 2021; since entering our dictionary in April 2026 it has already moved from 1.44% to 1.60% — the fastest-growing mailbox entry in the dataset.
The ESP layer unbundled
The sending side tells a different consolidation story: away from all-in-one marketing suites, toward raw infrastructure. Amazon SES grew from 1.51% of SPF-publishing domains in 2016 to 2.86% in 2022 to 6.21% today — a 2.2× jump in four years, making it the #1 ESP on the internet by domain count.
Mailchimp — the defining brand of the previous era — peaked at 5.03% in November 2022 and has slid to 3.69%. And then there is Mandrill, the dataset's best argument that infrastructure never dies: it peaked at 5.58% back in 2016, was famously "sunset" as a standalone product that same year, and still sits in 3.37% of SPF records a full decade later. DNS records outlive product roadmaps by years.
Authentication finally moved — sideways, then up
DMARC is the decade's qualified success. 459,124 top-1M domains now publish a policy. But 234,559 of them — 51% — sit at p=none, monitoring mode that blocks nothing. Enforcement (quarantine or reject at full coverage) stands at 47.16%.
The kink in the curves is the Google/Yahoo bulk-sender mandate of February 2024. It worked — as a compliance event. A wave of brand-new p=none records flooded the denominator, and the enforced share actually fell, from 46.91% in December 2023 to 42.04% in February 2024 and 40.98% by June 2024, before recovering to 47.16% by July 2026. Absolute enforcement counts grew the whole time; the percentage dip was an artifact of mass minimum-compliance. And in June 2026 the dataset recorded a first: quarantine (114,824 domains) overtook reject (114,390). The internet is settling on the middle setting.
What consolidation did not touch
It would be easy to conclude that email is now a two-company market. It is not. Self-hosted infrastructure still covers 147,712 domains. Another 12.45% of the MX-publishing population — 81,514 domains — resolves to providers our 310+ classification patterns cannot name at all, spread across 36,377 unique unmatched MX hostnames: regional hosters, appliances, one-off setups. Roughly a third of the world's receiving infrastructure remains gloriously unconsolidated, and it behaves nothing like Gmail.
Reading the next decade
Three things to watch, all visible in DNS long before they make the news: whether Microsoft's 2.6× growth premium over Google persists; whether Cloudflare's free routing tier starts eating the SMB segment the way registrar mail once owned it; and whether the DMARC enforcement plateau breaks past 50%. We will not have to guess — the same scan that produced this article runs every night.
Every series in this article updates daily. The current snapshot is available as JSON at api/latest.json, and the full methodology — 17 sections, patterns, and known limits — is published alongside the report. Journalists and researchers are welcome to cite it; we appreciate a link back.