How to enforce SMTP AUTH in Postfix ?

Issue

Postfix is configured to authenticate against Active Directory however users are able to send emails without SMTP AUTH.

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Here are the common uses of Markdown.

Code blocks

~~~
Code surrounded in tildes is easier to read
~~~

Links/URLs

[Red Hat Customer Portal](https://access.redhat.com)