Why does the pop3 subdomain return the hostname's SSL certificate instead of the primary domain's certificate?

Question

Why does the pop3 subdomain return the hostname's SSL certificate instead of the domain's certificate?

Answer

Pop3 is not a default subdomain that cPanel configures as part of the mail service. If you would like to use the pop3 subdomain for mail, you will need to add an e-mail account to the pop3 subdomain. Once the e-mail is added, the Dovecot SNI file can be rebuilt using the following command:

/scripts/build_mail_sni --rebuild_dovecot_sni_conf

After the SNI configuration is rebuilt, the pop3 subdomain will work with mail connections.