It works wonders on Linux as a primary SMTP server. You as the administrator will not need to download security patches for this server because its author, Dan Bernstein , wrote it from the ground up for security. The last time it required an update was in 1998, and it has never has needed a security update. The configuration is so easy that the server requires virtually no maintenance. They have the money to buy any mail server they want, but they chose qmail.
Most daemon programs run on Linux as the root user.
The other mail servers like sendmail , postfix , and exim do as well. The security problem with running programs as root is that if a hacker gains control of the server program then he also gains control of the entire server. Since these programs are so small and efficient then there is virtually no way for a hacker to gain access. For a more detailed list of the benefits of qmail, click here . It attempts to complement the excellent Life with qmail document, written by Dave Sill.