[Mailman-Users] data/aliases is created by mailman? or manually?

[Thufir]

In going through an Ubuntu guide:

"This build of mailman runs as list. It must have permission to read 
/etc/aliases and read and write /var/lib/mailman/data/aliases. Do this 
with these commands:

sudo chown root:list /var/lib/mailman/data/aliases
sudo chown root:list /etc/aliases"

https://help.ubuntu.com/community/Mailman#Postfix_Configuration

is data/aliases created by mailman?  Or, do I manually create that file? 
  How do I know that the aliases are correct?


see:

http://marc.info/?l=postfix-users&m=134615669604847&w=2


thanks,

Thufir