Hi, We have multiple mail domains hosted on ISPconfig multiserver setup. On client side we use popcon connector to distribute emails to exchange servers. However end clients using outlook are getting ssl waning mismatch everytime starting the service. We are using their domains(mail.example.com) for incoming/outgoing server, but outlook detects our mail server's SSL certificate flagging it as mismatch. What would be best solution for this issue? Tried to create websites for domains with valid certificate, but it still flagged on outlook. Also tried to create and SNI file for Dovecot and added these lines into postfix main.cf (followed from this script Postfix / Dovecot SNI for Letsencrypt certificates via cron script (auto) | Howtoforge - Linux Howtos and Tutorials): tls_server_sni_maps = ${indexed}sni indexed = ${default_database_type}:${config_directory} But must have messed up the syntax as this generated error for postfix in mail log.