I have the Helm email appliance, and what it does _not_ come with is a webmail interface. (It does have Nextcloud, though). I put Cypht on a different box to access my Helm mail, and it was very useful.

At the moment it is down because I did a migration from one host to another, there is some sort of login problem on the new box with the old database. RSN I'll have time to diagnose and fix.