After reinstalling my system (migrated from Centos to Gentoo 2007.0) I made a big mistake. I overwrote gentoo /etc/passwd file with my old one to restore my user list. After that I tried to install mailman and found alot of problem. First, mailman ebuild has a fixed number for mail group (280) instead of detecting it. I had to manually change group numbers to match it and reinstall postfix. After that, the build installed correctly, but doesnt works. When I use the start script simply fails without leaving any message. I run mailman and it starts ok, but when a mail is sent to any mailing list I get this error mail:
Command died with status 2:
"/usr/local/mailman/mail/mailman post red-admin". Command output: Group
mismatch error. Mailman expected the mail wrapper script to be executed as
group "postfix", but the system's mail server executed the mail script as
group "nobody". Try tweaking the mail server to run the script as group
"postfix", or re-run configure, providing the command line option
`--with-mail-gid=nobody'.

How can I fix this?