yes... a single Unity server can handle subscribers homed on any number of Exchange 5.5 servers in the same site or any number of message stores in a routing group for Exchange 2000.
Unity can service users on different Exchange servers in the same site / routing group.
We are investigating different ways to get around this but nothing is coming down the pipe soon.
Can I seperate subscribers ass UM and VM only subscribers on two exchange servers, like the enterprise exchange server exchange 2000 will be for UM and the exchange server exchange 2000 installed on unity will have VM subscribers only,
Currently Unity only supports all UM or all VM licenses on a single box... you can't mix and match VM and UM on the same Unity server.
can I set the attributes of the subscriber for VM only with UM licencing, lets take an example an enterprise has an exchange server 2000 which will be used for UM, the exchange 2000 installed on unity server will have VM subscriber only. Can it be configurable, so that I can manipulate the space requirements on both of the servers,
Not a problem... if you have UM licenses on that Unity box you can still home users on the on-box exchange server and use them for VM only mailboxes...
Can I take this question one step further?
My customer has got UM licenced Unity only and wants to deploy failover. Therefore Exch must be "off box". Can I have VM users as "dummy exch users" with exch off box? so messages are stored on the customer exch servers. (This would only be a small number of VM users (100) the majority are UM.)
I'm not sure I understand what you're asking here... if you have UM licenses (all licenses on a Unity box are the same - you can't mix UM/VM licenses on the same box) then what are these "small number of VM users" you're talking about?
If you're aksing if you can have some VM users on the same Unity server that you have UM users, the answer is no... the liecensing scheme doesn't allow mixing for whatever reason.
Jeff, Steve has customer who will have say 300 users, but only wants to provide voicemail to a few (this is an alternative to running another 2 x Unity platforms with OFFBOX VM only with failover ). Can he then have dummy Exchange users OFFBOX, that are therefore not UM but will use VM only. This allows him to support UM and VM only with 2 x Unity platforms with failover, but customer pays for UM licenses for all.