I need an ISPConfig expert

Hi, please read before contact me. I have a VPS with Ispconfig, I have configured about 4-5 website and it works good. I have a problem with Let's Encrypt certificates: via browser the SSL is ok, in [login to view URL] not! Example: The hostname of server is [login to view URL] I have configure a website: [login to view URL] and i have created an email "info @ [login to view URL]", i have enabled Let's encrypt SSL for this site. When i go on website with browser the SSL is ok. When I configure an email client to [login to view URL] it doesn't work because the certificate is pointed on server hostname "[login to view URL]" ... I would like my customers to be able to configure their mailboxes with the SMTP and IMAP server: [login to view URL] and not myserver.example.com. So I think it is a little problem with dovecot and postfix configuration. I need a real expert in ISPCONFIG server pls Thank you