Watchers works for email, not web?

Am I doing this wrong? I set up a group of staff users,
‘systems’, and assign them as AdminCC Watchers for the
’systems’ queue.

When I init a ticket via email, works fine, the
group address is put on as AdminCC.

But when I init a ticket from the web, either
directly into the systems queue, or in some other queue
and then transfer that ticket to the systems queue,
the systems group is NOT put on as AdminCCs.

Second problem: even with email, RT assumed that
the systems group would be refered to as ‘systems@hostname’.
Where can I change that? I don’t want the hostname of
this machine advertised, I prefer to use a CNAME. And
I already used ‘systems’ as a public email address,
so I prefer a different one for the group.