Here is an brief description of an *internet user* (from sac):
If the user is a Scalix mail user, then these are all aliases for the user's mailbox.
If the user is an external user, then only one external mail address should be provided.
Can I forward messages to that Internet User?
You (or anybody) can always "forward" the email to a recipient, just by *sending* it directly to the external user. But maybe this is not what you want.
If not, is there a mechanism to forward messages sent to a Scalix account to a non-Scalix user?
I guess what you want then is to send an email to a "fake" user on the scalix server, in another words, to an user that does not actually have a mailbox on the server, but still looks like a valid user on the scalix domain. I think you can do this just by editing the /etc/aliases file and putting an entry similar to ...
fakeuser: external_user_email
Then give the command "newaliases". The net effect is for the email to just bounce off the scalix server and out the door to teh recipient.
I think scalix has a sxaa tool or om* script to do the same thing.
Jaime