- Plesk for Linux
- Plesk for Windows
- Webmail shows warning insecure certificate although Let's Encrypt certificate is installed for the domain;
- Checking the certificate in the browser under Chrome > Certificate > Details > Subject Alternative Name, shows that the certificate is not issued for webmail:
The webmail is not secured.
Secure webmail according to the article How to secure webmail using Let's Encrypt in Plesk Onyx?