Redhat:Email Security

General User Security

The default security of a mail server allows all users to use the local smtp mail server with out a password. This can be changed in the configuration of both postfix and sendmail.

One way to change this is to prevent users to from logging into the email server at all by stopping them haveing a login shell in the /etc/passwd file. A user can set up an email manager connect to the email server.

Authentication

Access to the server is limited to to configured users, which is authenticated using the SASL. Both Postfix and Sendmail configure the autentication with a line in their main config file:

pwcheck_method=saslauthd

SASL's config file then itself defines the authentication method is /etc/sysconfig/saslauthd:

MECH=pam

Mail Logging

Messages relating to the Mail server can be found in the /var/log/messges file. This will include messges relating to restarts, user connections and messgaes.

Common Security Issues

The default port for email servers in port 25. This port must be open in the firewall to allow access.