Hi Togehter Since i can different now Mailboxes to Roundcube / Exchange on same domain, i'll get users also Access to the "Webmail" / "Owa". Roundcube is still reachable and working on domain.tld/webmail For Exchange Server (OWA) i would use outlook.domain.tld or something else. So first i did on the Test-Domain a DNS entry for the outlook.domain.tld And now i'm on my Problem. I only have one fixed external IP-Address. If i add for Subdomain ob Websites the internal Domain it's not reachable from external. So i think there should be a "portmapping" or something like on the reverse proxy on ISPCONFIG self. If it's possible i would do simmelar like the webmail for all customer. i also don't care if it's solved by subdomain or /owa or whatever. It just should work and if possible be the same for all customer. There is also the Question about the HTTPS. Do deliver the ISPCONFIG3 the cert? Or do anyone know how to copy the cert automaticly to Exchange Server? Thank you guys!