[cobalt-users] RAQ4: Lists do not work without 'www'

["Benoit Sarton" <bs@xxxxxx>]

We are trying to add lists on a new raq4, exactly like we did hundred times on the raq2
They do NOT work when sending submissions to  listname@xxxxxxxxxx
They work with listname@xxxxxxxxxxxxxx

domain.org is in both ' relay for the following hosts domain' and 'host.domain aliases'
( Simple user mail adresses work fine with both @domain.org and @www.domain.org )

I have tried ( in vain ) to add the following line to /etc/mail/virtusertable : 
listname@xxxxxxxxxx   listename_sitexx

Would that mean that it is a majordomo config problem, rather than a sendmail problem ?
Is it another bug of the raq4 gui ? 
Can I configure the list by hand ?

( I have applied all published patches for the raq4 )
thanks for help