The first version of SNI support for Mail is available in Plesk Obsidian: https://docs.plesk.com/release-notes/obsidian/change-log/#18-rc10
You need MailEnable 10.20+ (for Windows) or Postfix 3.4+ and Dovecot (for Linux) to test it.
There are cases when it doesn’t work (e.g., if you connect to mail.domain.com it will not work, please use domain.com in connection settings of your mail client) that’s why we don’t mark it as “available”. We plan to fix these issues soon.
— rkAnonymous commented
Thank you for your input! We will consider this functionality in upcoming releases if it will be popular.
Everyone, please continue voting for this feature if you consider it important.
Upd: Suggestion is reopened.