I installed ISPConfig 3.0.5.1, with Apache, Postfix, Dovecot on a CentOS-flavor system. I made the language correction and disabled CGI with domains I am testing for Mailman use. I can send and receive emails externally and int5ernally with SquirrelMail. I can create Mailman lists from the ISPConfig interface. I can add subscribers through the web and they receive email confirmation requests from [email protected]. If I click the link, the subscriber is added. However, if I reply, the email is sent back with a permanent fail. I also get a permanent fail if I try to post, using the [email protected] and list prefix in the subject line. I've tried setting up with non-subdomains as well (mydomain.com). I get this error in my maillog: