Global Mailserver Map (inbound) 2021

A complete map of the infrastructure and technology which empowers 4.5 bn people to communicate each day.
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% of Nodes Are Open Source

Two mail server applications lead the market totalling 72%. Proprietary (closed source) products are just 8%.

% of Nodes are managed in-house

Outsourcing of mailserver management is the minority at 23%! All other servers are partly or fully self-managed.

Server Nodes in Countries

All countries that we scanned have mailservers. 24% are located in the USA. Explore countries below.

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USA self-hosted mailservers
EU countries all mailservers
Software run on badly setup mailservers
Software license
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Total count
of all mailservers

Email’s Diversity Delivers Value

Email speaks everyone’s language because it is an open and decentralised ecosystem. It has been a platform for innovation for over 50 years. Lightmeter makes managing the world’s most popular mailserver convenient in an Open Source package..

Research Methodology

We scanned servers etc. Ecluded certain ranges etc. Limited to IPv4. Used 3 second timeout. DNS record-based investigation. Excluded hyper-cloud hosts (GAM)!. Excluded outbound-only email nodes. Rely on self-reporting of software used. More details in the dedicated blog.

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