The share of major websites running their own email servers dropped by half over the past decade, falling from 44.6 percent in 2016 to just 22.4 percent in 2026, according to research published by Artem Berezin, a researcher at business email company Live Direct Marketing, on the Internet Society blog. The analysis reveals that Google and Microsoft now control nearly 40 percent of email infrastructure among the world's most popular domains, raising concerns about centralization and systemic risk in a critical communication channel.
Berezin examined DNS records for the top million domains using daily snapshots from the OpenINTEL project, run by the University of Twente, SURFnet, and SIDN Labs, combined with popularity rankings from the Tranco project. Self-hosted mail servers remain the single most common approach to handling email, but Google Workspace now accounts for 21.8 percent of detectable MX records, while Microsoft 365 holds 16.8 percent. Together, the two tech giants handle 38.6 percent of email traffic among popular domains. The decline in self-hosting accelerated recently, dropping by half a percentage point in just 30 days. Berezin's analysis also found that more than half of DMARC records either lack a valid policy or simply monitor email without enforcing authentication policies, despite Google and Yahoo mandating DMARC requirements for bulk senders in 2024.
Berezin draws a parallel between email centralization and ongoing discussions within the RIPE NCC community about DNS and content delivery network consolidation. "When more than a third of popular domains depend on two providers to receive mail, an outage, a filtering change, or a policy decision at either one propagates through the whole ecosystem at once," he wrote, noting that unlike CDNs, email offers no graceful fallback when messages are rejected. The researcher also points to a secondary problem: as fewer independent operators remain, those who continue self-hosting inherit deliverability challenges in an ecosystem tuned for the big two providers.
The concentration creates a self-reinforcing cycle, according to Berezin's analysis. Google and Microsoft operate filters designed to block messages they consider untrustworthy, making it difficult for operators of fresh mail servers using platforms like Postfix to achieve acceptance at scale. This drives marketers and businesses toward the dominant providers to ensure their messages reach recipients. The researcher acknowledges his dictionaries don't capture the complete landscape of email infrastructure, leaving significant portions invisible to analysis. He poses questions his data can't yet answer: at what concentration does inbound mail become a systemic dependency requiring explicit community attention, and what would actually push DMARC from published to enforced given that 2024 mandates failed to achieve that goal?
Berezin can't resolve those uncertainties but continues daily downloads of email server data in hopes of eventually finding answers. His ongoing analysis aims to illuminate how much of the Internet's mail infrastructure remains hidden from view and whether the current trajectory toward centralization warrants intervention. For organizations still weighing infrastructure choices, the tension between operational convenience and ecosystem resilience has never been sharper. Ceding control to platforms that also set the rules for message acceptance transforms email from a distributed protocol into a gatekeeper-mediated service.