CloudLinux AlmaLinux OS 9 STIG Version Comparison

There are 5 differences between versions v1 r1 (Nov. 19, 2024) (the "left" version) and v1 r2 (April 2, 2025) (the "right" version).

Check ALMA-09-006845 was added to the benchmark in the "right" version.

This check's original form is available here.

Title

AlmaLinux OS 9 must have the postfix package installed.

Check Content

Verify that AlmaLinux OS 9 has the postfix package installed with the following command: $ dnf list --installed postfix Example output: postfix.x86_64 2:3.5.9-24.el9 @AppStream If the "postfix" package is not installed, this is a finding.

Discussion

Postfix is a free, open-source mail transfer agent (MTA) that sends and receives emails. It is a server-side application that can be used to set up a local mail server, create a null-client mail relay, use a Postfix server as a destination for multiple domains, or choose an LDAP directory instead of files for lookups. Postfix supports protocols like LDAP, SMTP AUTH (SASL), and TLS. It uses the Simple Mail Transfer Protocol (SMTP) to transfer emails between servers. Satisfies: SRG-OS-000304-GPOS-00121, SRG-OS-000343-GPOS-00134, SRG-OS-000363-GPOS-00150, SRG-OS-000447-GPOS-00201

Fix

Install the postfix package with the following command: $ sudo dnf install postfix