I have done extensive research to try and figure out why the smtp_bind_address directive in my Postfix config isn't working.
The pertinent parts of main.cf are:
inet_interfaces = all smtp_bind_address = 66.42.208.244
The pertinent parts of master.cf are:
smtp inet n - y - - smtpd -o content_filter=autoresponder:dummy -o smtp_bind_address=66.42.208.244
The actual IP address the mail comes from does not change to 66.42.200.244. From everything I have researched, the above should work.
I'm needing the IP address to change.