Complete Email Server section: different components

[vsessink]

The Complete Email Server section now shows a indifferent list of "complete mail servers", but IMHO there is a difference between solutions that consist of individual components, like postfix, dovecot, spamassassin; and those that are actual complete mail servers.

Mailu consists of at least Postfix, Dovecot, Ngingx, Rspamd (https://github.com/Mailu/Mailu/tree/master/core)
iRedMail does so, too: https://docs.iredmail.org/file.locations.html
Zimbra is an even more complex configuration of open source tooling (https://wiki.zimbra.com/wiki/Troubleshooting_Course_Content_Rough_Drafts-Zimbra_Architecture_Component_Overview)
Modoboa says it's Postfix and Dovecot again (https://github.com/modoboa/modoboa)

Mox and Stalwart are integrated full service mail systems. Would you like me to suggest a patch?