[cobalt-users] @domain.com.au exchange alias not working

["Dylan O'Donnell" <dylan@xxxxxxxxxxxxxx>]

Hi there.. The alias @domain.com.au for user 
should send any mail sent to 
test@xxxxxxxxxxxxx to user@xxxxxxxxxxxxx 

Here is my debugging output - 
--------------------------------------------
[root@virtual mail]# cat /etc/aliases.majordomo | grep domain.com.au
majordomo_site14:       "|/usr/local/majordomo/wrapper -v site14 -f
www.domain.com.au  majordomo"
--------------------------------------------
[root@virtual mail]# tail -50 /var/log/maillog | grep domain.com.au
Oct  7 12:04:23 virtual sendmail[10256]: MAA10256: <test@xxxxxxxxxxxxx>...
User unknown
---------------------------------------------


I can send mail to user@xxxxxxxxxxxxx and it gets there fine, so the mail
works ok and I have other domains that are set up identically and do accept
all mail for the doamin. Does anyone know what would cause one specific
domain to do this ? What files should I be looking in ? Where is that alias
for the domain defined? /etc/aliases.majordomo shows the correct data if I
compare domain.com.au's entry to the domains that work. 

note - domain.com.au is generic. Im working with a FQDN 

Cheers, 

Dylan Thomas O'Donnell
Dragnet Internet Servicessystem.