[Mailman-Users] "Host name this list prefers"

[steven]

Hi,

How do I get the field labelled "Host name this list prefers" on the
admin page "mailing list administration
General Options Section" to correctly handle a sub-domain (aka three
part machine name, e.g. foo.domain.com) so that mail sent from
adminstrative aliases comes from  
listname-admin at foo.domain.dom  instead of listname-admin at domain.dom ?

right now, if I use a subdomain/3 part machine name for an existing
virtual host (which is listed in all the appropriate files to give the
virtual host full permissions in sendmail.cf) it defaults to the domain
of the server's real domain.

i.e. if I enter 'foo.virtdoman.dom' in the "host name this list prefers"
the emails incorrectly come 'From:' 
listname-admin at realdomain.dom.  

Yet if I use only 'virtdomain.dom' in the "host name this list prefers"
then the emails do come from 'listname-admin at virtdomain.dom' as I would
expect.

Is there a config I've missed to allow the from address to use a
sub-domain/3 part machine name in the "From:" field?   Is it a bug?  Is
it a feature?  

Is there a particular item in a .py file I could edit to allow this?  

tia,
~steven