- Plesk for Linux
How to assign SSL certificate for all or a particular mail domain on a postfix?
Postfix mail server does not support assigning SSL certificates on a domain level.
As well as Postfix SMTP daemon does not support Server Name Indication (SNI). Additionally, according to official postfix documentation: "There are no plans to implement SNI in the Postfix SMTP server." Thus, SSL certificates can be assigned only on a server level or IP based.