[Mailman-Users] mail-gid problems

[Ming Jack Po]

Hey All,

I have a really weird issue.  I am currently running gentoo and just 
setup mailman (from source). 

Every time I setup.. I can use the lists normally in the beginning... 
make list .. lists function and all..

However, the moment I port some of my old data (the goal of this new 
installation is to get data from old installation to new one).

(move data from lists and archive directories to the new ones)

The installation immediately fails and outputs

Group mismatch error. Mailman expected the mail wrapper script to be 
executed as group "mailman", but the system's mail server executed the 
mail script as group "nobody." etc etc

I am using postfix, gentoo, mailman..

Any help would be very much appreciated,
Thanks,
Jack