The Red Hat Enterprise Linux operating system must be configured to prevent unrestricted mail relaying.
An XCCDF Rule
Description
If unrestricted mail relaying is permitted, unauthorized senders could use this host as a mail relay for the purpose of sending spam or other unauthorized activity.
- ID
- SV-204619r603261_rule
- Version
- RHEL-07-040680
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
If "postfix" is installed, modify the "/etc/postfix/main.cf" file to restrict client connections to the local network with the following command:
# postconf -e 'smtpd_client_restrictions = permit_mynetworks,reject'