OL 9 must have the s-nail package installed.

The s-nail package provides the mail command required to allow sending email notifications of unauthorized configuration changes to designated personnel.

Verify that OL 9 has the s-nail package installed on the system with the following command:

$ dnf list --installed s-nail Installed Packages s-nail.x86_64 14.9.22-6.el9 @ol9_appstream

If the s-nail package is not installed, this is a finding.

Install the s-nail package with the following command:

$ sudo dnf install -y s-nail