I installed ISPConfig 18.104.22.168, 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@example.com
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 firstname.lastname@example.org
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:
NOQUEUE: reject: RCPT from mail-ob0-f179.google.com[22.214.171.124]: 550 5.1.1 <email@example.com>: Recipient address rejected: User unknown in virtual mailbox table; from=<firstname.lastname@example.org> to=<email@example.com> proto=ESMTP helo=<mail-ob0-f179.google.com>