Setting up an SMTP Server on Linux – ultimate guide
Posted: Mon Dec 09, 2024 8:23 am
The Four Horsemen of Linux Mail Transfer: Exim, Postfix, Sendmail, and Qmail
Considering how important and popular email is today, it shouldn’t surprise anyone that there are millions of email servers currently operating on the public internet. According to a 2019 survey from securityspace.com il servers online!
Given the long history of email (dating back to 1971), and the guatemala phone number material massive number of email servers online, you’d be right to assume that there are many different email server platforms available. However, according to the securityspace.com survey, three types of email servers account for more than 95% of the global market share:

Exim
Postfix
Sendmail
The top three email servers on the internet are Exim (with over 55%), Postfix (over 30%), and Sendmail (about 4%). All three of these email platforms, and Qmail, were originally developed for Unix-Like or Linux based Operating Systems.
Today, with the widespread availability of easy and low-cost cloud-hosted server providers, anyone can setup their own email server. This guide focuses on deploying, configuring, and discussing best practices and security concerns for Exim, Postfix, Sendmail, and Qmail.
Exim – Overview + Pros & Cons
Exim is an MTA (Mail Transfer Agent) for Unix-like operating systems first written in 1995 by Philip Hazel. Exim is licensed under the GPLv2 license. Exim is used extensively all around the world. According to the study noted earlier r approximately 57% of all online public email servers on the internet. Exim4 is currently the default MTA on all Debian-based GNU/Linux systems, including Ubuntu.
Exim – Pros
Default MTA on Debian-based Linux distributions
Easy install, basic install is guided via user interface
Popular and well documented
Plenty of community support
Secure
Exim – Cons
Arguably more difficult to maintain/administer post-deployment than Postfix
Postfix – Overview + Pros & Cons
Postfix is an MTA (mail transfer agent) for Unix-like operating systems developed by Wietse Venema in partnership with IBM in 1997. Postfix is licensed under the IBM Public License. As of 2019, Postfix is still under active development by its creator and a team of contributors. According to the following sf 2019 Postfix accounted for approximately 34% of all online public email servers on the internet.
Postfix – Pros
Easy to configure and use
Elegant (author’s opinion)
Popular and well documented
Plenty of community support
Secure
Considering how important and popular email is today, it shouldn’t surprise anyone that there are millions of email servers currently operating on the public internet. According to a 2019 survey from securityspace.com il servers online!
Given the long history of email (dating back to 1971), and the guatemala phone number material massive number of email servers online, you’d be right to assume that there are many different email server platforms available. However, according to the securityspace.com survey, three types of email servers account for more than 95% of the global market share:

Exim
Postfix
Sendmail
The top three email servers on the internet are Exim (with over 55%), Postfix (over 30%), and Sendmail (about 4%). All three of these email platforms, and Qmail, were originally developed for Unix-Like or Linux based Operating Systems.
Today, with the widespread availability of easy and low-cost cloud-hosted server providers, anyone can setup their own email server. This guide focuses on deploying, configuring, and discussing best practices and security concerns for Exim, Postfix, Sendmail, and Qmail.
Exim – Overview + Pros & Cons
Exim is an MTA (Mail Transfer Agent) for Unix-like operating systems first written in 1995 by Philip Hazel. Exim is licensed under the GPLv2 license. Exim is used extensively all around the world. According to the study noted earlier r approximately 57% of all online public email servers on the internet. Exim4 is currently the default MTA on all Debian-based GNU/Linux systems, including Ubuntu.
Exim – Pros
Default MTA on Debian-based Linux distributions
Easy install, basic install is guided via user interface
Popular and well documented
Plenty of community support
Secure
Exim – Cons
Arguably more difficult to maintain/administer post-deployment than Postfix
Postfix – Overview + Pros & Cons
Postfix is an MTA (mail transfer agent) for Unix-like operating systems developed by Wietse Venema in partnership with IBM in 1997. Postfix is licensed under the IBM Public License. As of 2019, Postfix is still under active development by its creator and a team of contributors. According to the following sf 2019 Postfix accounted for approximately 34% of all online public email servers on the internet.
Postfix – Pros
Easy to configure and use
Elegant (author’s opinion)
Popular and well documented
Plenty of community support
Secure