I used to run postfix/ssmtp/etc on Gentoo. From time to time, when updating the single components, something stopped working and then I had to quickly debug and

I used to run postfix/ssmtp/etc on Gentoo. From time to time, when updating the single components, something stopped working and then I had to quickly debug and find a fix. In the end it was too much time-consuming for me to maintain. I then decided to search for a big-monolithic-do-it-all-solution (from a SW-perspective) and the only option I found was Xeams ( https://www.xeams.com/Xeams.htm https://www.xeams.com/Xeams.htm ) - I didn't find anything open-source. I'm using it (the free variant) since 2017 and it works. Runs on Java, provides all services (smtp, pop3, imap), has greylisting, has embedded user administration, users can have email-aliases, has a web-admin-UI, 1-click-sw-updates, etc... .