@scottalanmiller
If you are referring to my "not truly ready for commercial use" comment:
With commercial use I meant "commercial mail hoster". An example would be the fact that mailcow uses Let's Encrypt to give each handled domain a SSL certificate, but that puts a limit of a 100 domains per server: https://github.com/mailcow/mailcow-dockerized/issues/461
Also, it is not easy to add high availability
Otherwise, it is a very good platform. I have production servers and hundreds of mailboxes
Edit: Commercial e-mail hoster is better than previous commercial web mail hoster