Mine

# Default to using the FQDN of machine mailman is running on.
# If this is not correct for your installation delete the following 5
# lines that acquire the FQDN and manually edit the hosts instead.
VIRTUAL_HOSTS_OVERVIEW = Off
DEFAULT_URL_HOST   = "www.horizong.com"
DEFAULT_EMAIL_HOST = "horizong.com"

# Because we've overriden the virtual hosts above add_virtualhost
# MUST be called after they have been defined.


add_virtualhost(DEFAULT_URL_HOST,DEFAULT_EMAIL_HOST)