SSL/TLS certificate for mail is not automatically updated by Let’s Encrypt in Plesk

Symptoms

• After the automatic Let's Encrypt renewal process finishes, the certificate for mail.example.com is not updated, and the following message is displayed:

  Let's Encrypt does not support mail certificate auto-renewal. To renew the mail certificate automatically, install the SSL It! extension.

• SSL It! extension is not installed under Extensions > My Extensions > SSL It! page.

Cause

Standalone version of Let's Encrypt does not support auto-renewal of mail certificates.

Resolution