1) Add cpcalendar, cpcontacts, mail and webmail A records pointing to your sever’s IP. make sure the Procy Status (Cloud) is OFF (DNS only)
2) Once this records are properly set up, back in cPanel we will open SSL/TLS Status, here we will generate an Auto SSL, but before remove any subdomains that are not going to be used.
For example if your domain is hosted somewhere else remove the main domain and the www subdoamin. you might find some weird addresses like www.domain.mailserver.com, you can also Exlude those before running the AutoSSL.
3) Once you have excluded all the unwanted addresses, click Run AutoSSL, this might take a while depending on how many domains you have so, prepare a coffee and sit tight.
If everything went well you will see green locks next to all your addresses:
4) Now we are ready to use the secure connections provided by Cpanel, go to Email Accounts -> and select the desired account and click on Connect Devices. There you will see all the necessary information to connect suing SSL/TSL