mail.domain.tld with SSL Cert

The way I had it configured and working was to create a website with hostname.genericdomain.tld and then create alias domains for that domain for each mail.domain.tld.

I then had symbolic links at /usr/local/ispconfig/interface/ssl/ and somewhere else, I remember reading how to do it on this site, but for the love of all that is unholy, I can't find the post.

Lately when I add an alias domain for mail.domain.tld, the mail client is not getting the cert. Yes clients can use hostname.genericdomain.tld but if I switch a client to a new server it's the headache of getting them all to change the IMAP and SMTP server name.

Browsing through the server, I see that there is now PEM Certs at /usr/local/ispconfig/interface/ssl/

How do I get IMAP and SMTP to use same cert as hostname.genericdomain.tld?

EDIT:

What I want is if you open hostname.genericdomain.tld on port 443 or 8080 the cert is true. On port 443 I am offering a Roundcube loging.

I also want mail.client1.tld, mail.cilent2.tld, etc to all have valid certs for IMAP and SMTP.

If I run

Code:

nmap --script ssl-cert -p 465 hostname.genericdomain.tld

then all the mail.clientx.tld names are in the certificate, but not when I run

Code:

nmap --script ssl-cert -p 993 hostname.genericdomain.tld

 

Fix:

systemctl restart dovecot && systemctl restart postix

This wasn't a step I had to do in the past, so in a recent update something has gone a stray?