How do I configure Postfix to use Simple Authentication Security Layer (SASL) with Transport Layer Security (TLS) on Red Hat Enterprise Linux 4?

Using Postfix with SASL allows an email administrator to force users who access the mail server from an untrusted location to authenticate with their user name and password. Adding TLS provides encryption for the password transaction. This is a primary method of protecting the mail server from being used by spammers while simultaneously protecting user account information. Note that this artic...