NethServer Version: 7.3.1611
I just spend a 2 hours to find out that recipient completion is not working when roundcubemail is started via a virtualhost (https://server.sld.tld/webmail). I get an error “Serverfehler! (Internal Server Error)”. No logentrys for this error. When roundcubemail is called via https://servername/webmail everything is working.