Disable support for anonymous authentication

Debian 9
webmin 1.962

My mail server is showing that I have anonymous authentication vulnerability.

Is there a way to disable support for anonymous authentication to mitigate this vulnerability in webmin? or Do I need to enable Reject plain-text logins in postfix and will this cause any other issues?

any thoughts on this will be appreciated.

Have you tried “Reject anonymous logins” in Postfix “SMTP Authentication And Encryption”?

Richard

yes, Reject anonymous logins is checked