Self-Hosted Email Servers Rapidly Declining
Microsoft and Google dominate email infrastructure.
1Decline of Self-Hosted Email Servers
Over the past decade, the number of large users hosting their own email servers has halved. According to Artem Berezin’s analysis, while 44.6% of the top million domains used their own servers in 2016, this figure is expected to drop to 22.4% by 2026. This decline highlights the shift towards tech giants like Microsoft and Google in email infrastructure.
2Role of DNS Records
Berezin uses DNS records to analyze email servers. MX records indicate where the mailbox resides, SPF records specify which sources can send emails, and DMARC records define how to handle emails that fail authentication. These records are crucial for understanding the centralization of email infrastructure.
3Dominance of Tech Giants
Google Workspace and Microsoft 365 are increasingly dominating email infrastructure. By 2026, Google Workspace holds 21.8% of detectable MX records, while Microsoft 365 holds 16.8%. Together, these two giants handle 38.6% of global email traffic, raising concerns about centralization.
4Risks of Centralization
Berezin warns about the risks of email infrastructure becoming dependent on Microsoft and Google. An outage or policy change at either company could impact the entire ecosystem. Unlike CDNs, email has no fallback mechanism; a rejected message is simply lost.
5Weakness of DMARC Records
DMARC records are used to authenticate emails. However, Berezin’s research shows that over half of DMARC records either lack a valid policy or do not enforce policies. This persists despite Google and Yahoo’s 2024 mandate requiring DMARC usage.
6Decline of Independent Operators
As the number of independent email operators decreases, the remaining ones must adapt to the dominance of tech giants. Berezin cites the challenges faced by those trying to set up new Postfix servers in 2026 as an example. This trend threatens the existence of independent operators.
7Impact of Email Filters
Google and Microsoft use filters to detect emails from untrusted sources. These filters often reject emails from independent servers, pushing marketers to rely on major tech providers to ensure their messages are delivered.
8Future of Email Infrastructure
Berezin emphasizes that the centralization of email infrastructure poses serious risks to global communication. Like DNS and CDN centralization, email infrastructure is quietly following a similar path, placing control of a fundamental internet component in the hands of a few companies.