So i don't know if this is normal condition or mistake somewhere but it's bugging me alot. These two guides has been followed: https://www.howtoforge.com/tutorial...-9-stretch-apache-bind-dovecot-ispconfig-3-1/ https://www.howtoforge.com/tutorial/securing-ispconfig-3-with-a-free-lets-encrypt-ssl-certificate/ All FTP connections, and mail are using the same certificate which has been set to server hostname which is basically a main domain. And when using software like thunderbird and filezilla it's showing me a warning that certificate don't match domain when i try to connect with other domain names even though they have it's own SSL. Why don't they use always certificate from the domain name used on connection? Is that not possible or i made mistake somewhere along the setup?