[Mailman-Users] Group mismatch error (mail wrapper script)

[Rosenbaum, Larry M.]

I'm migrating Mailman to a new server and getting the following error when I send mail to a list:

#5.3.0 x-unix; Group mismatch error. Mailman expected the mail wrapper script to be executed as one of the following groups: [mail, postfix, mailman, nobody, daemon], but the system's mail server executed the mail script as group: "users". Try tweaking the mail server to run the script as one of these groups: [mail, postfix, mailman, nobody, daemon], or re-run configure providing the command line option: '--with-mail-gid=users'.>

Where do I need to look for the error?

Running Mailman 2.1.14 on RHEL6 with Postfix.

Larry M. Rosenbaum
Oak Ridge National Laboratory