[Mailman-Users] mailan and postfix config problems

[soportek]

I am migrating mailman lists from somedomain.org to lists.somedomain.org

I can create new lists for lists.somedomain.org and receive mail from
the list but sending mail to lists.somedomain.org results in

" Recipient address rejected: User unknown;"

I know this is postfix related but I am follwing the postfix config
INSTALL instructions from /var/lib/mailman/bin/postfix-to-mailman.py

and I have edited...

/etc/postfix/main.cf
/etc/postfix/master.cf
/etc/postfix/transport
/etc/mailman/mm_cfg.py

..as per those instructions.
I have also read these guides which provide more or less identical
instructions.
http://wiki.debian.org/Postfix#Mailman_with_Postfix
http://library.linode.com/email/mailman/debian-6-squeeze

The relevant section of my /etc/postfix/main.cf looks like this

  alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
  alias_database = hash:/etc/aliases
  virtual_alias_maps = hash:/etc/postfix/virtual
  local_recipient_maps   = $alias_maps, proxy:unix:passwd.byname

  relay_domains = $mydestination, lists.somedomain.org
  relay_recipient_maps = hash:/var/lib/mailman/data/virtual-mailman
  transport_maps = hash:/etc/postfix/transport
  mailman_destination_recipient_limit = 1


Something I find odd is that with the above config is that when I create
a new list nothing is being written to the file:
  /var/lib/mailman/data/virtual-mailman

I understood that should happen automatically.