I used to run CommuniGate from Stalker on my private mail server.
It is more or less one binary and one data folder, available for all operating systems, providing a lot of functionality (SMTP, IMAP, ActiveSync, Webmail, Groupware, ...). Everything can be configured via one uniform Web UI. Multi domain, multi IP, and you could even cluster together multiple servers.
It's closed source, but offers a free license for up to 5 mailboxes.
Sadly this product died during the last 10 years and is now in an unusable state.
It is more or less one binary and one data folder, available for all operating systems, providing a lot of functionality (SMTP, IMAP, ActiveSync, Webmail, Groupware, ...). Everything can be configured via one uniform Web UI. Multi domain, multi IP, and you could even cluster together multiple servers.
It's closed source, but offers a free license for up to 5 mailboxes.
Sadly this product died during the last 10 years and is now in an unusable state.