RHEL 9 must have the Postfix package installed.

Documentable No

Rule ID SV-272488r1155665_rule

CCI References

CCI-000015

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 such as 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

Check Procedure

Note: If the admin can demonstrate that there is another system/service to send audit failure notifications to the administrator/ISSO, this control is not applicable.

Verify RHEL 9 has the Postfix package installed with the following command:

$ sudo dnf list --installed postfix

Example output:

postfix.x86_64                             2:3.5.25-1.el9 

If the "postfix" package is not installed, this is a finding.

Fix Action

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