Thank you for the replies. The original source of my confusion was assuming that all information received with the HELO or EHLO command would be processed by the smtpd_helo_restrictions.
I understand now that that the text under http://www.postfix.org/postconf.5.html#smtpd_helo_restrictions includes the following implicit and unwritten statement: These restrictions are not applied to the address literal information received with the HELO or EHLO command. Thus, I was indeed trying to do something unsupported. - James
