The Postfix program
<lenhador-news@saturno.fazendosistemas.com.br> (expanded from
<lenhador-news@lenhador.com>): Command died with status 2:
"/usr/local/mailman/mail/mailman post lenhador-news". Command output: Group
mismatch error. Mailman expected the mail wrapper script to be executed as
group "nogroup", but the system's mail server executed the mail script as
group "mailman". Try tweaking the mail server to run the script as group
"nogroup", or re-run configure, providing the command line option
`--with-mail-gid=mailman'.