Outlook 2003 terminal server

If I install a retail copy of outlook 2003 on a Terminal Server, will it
need activating once? Or will it activate for the first user then not for
the others? I dont really get how this all works, we bought a copy of
exch.2003 for a test server (our real server is exch 2000). The outlook 2003
that came with it activated around 5 times (presumably because the exhcange
includes 5 cal's), now it wont any more. How can I get this to activate
again, as our supplier doesn't seem to sell outlook licenses (and if they
did, how do I enter them?) After all, what if you had 500 users requiring
it? Help!