We were restricting the ability to send email to specified distribution lists as described in the wiki document RestrictPostfixRecipients. We had it working under ZCS 6.x, but since we have upgraded to ZCS 7.1.1 it does not work.

I have checked and the modifications I made to the main.cf file are still there, post upgrade. I see no errors in any of the log files.

I'm not sure what to try now...