[cisco-voip] Unity (integrated) questions vis-a-vis Outlook, VMO and a separate Exchange server

[Netfortius]

Could someone point me to a very thorough description of the architecture of 
Unity - the integrated version (the one with "built-in" exchange data 
store) - and its relationship with that Exchange data store, Outlook 
capabilities as MAPI client for an existing Exchange email server, VMO usage 
in such an environment, etc.? Here are a couple of things I am trying to 
answer, associated with a deployment of such:

- if Outlook is a MAPI client - could I "go" after the messages in an 
integrated unity environment (its exchange data store) as if it was an 
exchange server?
- if the above is true (which I think it is, simply because the OWA is 
supposed to do the same thing), and knowing that Outlook can only accept an 
Exchange serve account at a time - is there any relationship I could 
establish between the data store associated with the unity and an Exchange 
server already used as email server, such that I can get the voice messages 
from unity/exch data store in the same time with emails (trust + 
<something>)?
- what is the VMO role in such an environment? If it is capable of creating 
voice messages to be sent to other mailboxes, isn't that equivalent to being 
able to be a "MAPI" client of the unity data store, or use Outlook for such - 
and - under this scenario - wouldn't this allow "pulling" into some Outlook 
local folder voice messages, from the unity data store, while Outlook is also 
an email client of the mail Exchange server?

I am sorry if the above questions do not make much sense, but I am trying to 
gain a better understanding of this architecture, and I am not sure how 
things actually work (some people even telling me that VMO is not merely an 
Outlook form, but also having some DLLs associated with it, upon 
installation, which allow it to communicate directly with the Unity 
server?!?)

Oh - we'll be using Unity ver 4.2.

Pointers to RTFMs, books, links, etc will be appreciated

TIA,
Stefan