Hello,
when I send mail a mailinglist using mailman 2.1.5 and postfix 2.1.5 on
a debian sarge system I get:
Group mismatch error. Mailman expected the mail
wrapper script to be executed as group "list", but
the system's mail server executed the mail script as
group "root". Try tweaking the mail
> >Meanwhile I noticed that I get the same error, even if I move the
> >mailman file away.
>
>
> The group mismatch error is coming from some Mailman mail/mailman
> wrapper, so if you move yours aside and still get the error, Postfix
> is piping to a different wrapper.
>
> Look at your Postfix