Personally i use a mail server that's preconfigured and lives inside of a Docker container with all of the dependencies that it needs: https://hub.docker.com/r/mailserver/docker-mailserver ( GitHub: https://github.com/docker-mailserver/docker-mailserver ). With it, adding a new e-mail account is as simple as running a script with some parameters and it interoperates nicely with most clients such as Thunderbird or even the one built into Nextcloud (for a lightweight hosted solution without a separate app to manage).
It is pretty awesome to see new projects that try to improve the user experience for the system admins, for example, the Caddy web server and now the Maddy mail server. I'm not sure whether i'd have been able to set up a mail server the "old fashioned way", seemingly in line with the concerns of the other people here who have tried that more extensively. Somehow, while e-mail is super widespread and works decently for getting text information from place A to place B, it also feels a tad overcomplicated (the different components for sending/receiving mail, SMTP, IMAP, POP3, the sad need for anti virus scanning, SPF, DKIM, DMARC, the similarly sad need for anti spam protection).
That said, the containerized solution above has also worked nicely for me - i'll still probably use GMail/other hosted solutions for personal e-mail stuff and communication, but right now i've already switched over to using my own mail server for all of the automated e-mails that i need, such as from SonarQube and Zabbix, as well as GitLab.
I tried it recently and was irritated that it doesn't play nicely with a existing LetsEncrypt instance on the host. Docker doesn't like mounting symlinks, and LetsEncrypt uses symlinks to point to the latest live certificate and key. I could configure Certbot (LetsEncrypt) on deployment of a new certificate to copy it to the Docker instance and tell it to load it, but at this point I just fished out my old Postfix and Dovecot configurations and notes and did it myself; at least this way I'm in complete control.
I do approve of such a project existing though, and if I wasn't running other things on the host I would probably use it.
It is pretty awesome to see new projects that try to improve the user experience for the system admins, for example, the Caddy web server and now the Maddy mail server. I'm not sure whether i'd have been able to set up a mail server the "old fashioned way", seemingly in line with the concerns of the other people here who have tried that more extensively. Somehow, while e-mail is super widespread and works decently for getting text information from place A to place B, it also feels a tad overcomplicated (the different components for sending/receiving mail, SMTP, IMAP, POP3, the sad need for anti virus scanning, SPF, DKIM, DMARC, the similarly sad need for anti spam protection).
That said, the containerized solution above has also worked nicely for me - i'll still probably use GMail/other hosted solutions for personal e-mail stuff and communication, but right now i've already switched over to using my own mail server for all of the automated e-mails that i need, such as from SonarQube and Zabbix, as well as GitLab.