The Web Storage System URLs are constructed in the
		  following manner:
 Aliases do not necessarily represent a unique
		  mailbox, and they have nothing to do with the data of the path user. User
		  object Simple Mail Transfer Protocol (SMTP) addresses are used to identify the
		  path to a mailbox in Exchange 2000, and they must be unique (note that you may
		  also use a secondary SMTP address for this purpose).
 This match is
		  done by adding the left hand side (LHS) of your mail attribute to the primary
		  SMTP address from the default recipient policy. This must match any of the
		  entries in your proxy addresses.
 Therefore, the domain at the root of
		  drive M (and correspondingly, the path to which the Exchange IIS virtual
		  directory points) is used to identify which mailbox is being
		  accessed.
Username@
domain.com
		  = left-hand-side@right-hand-side (or LHS@RHS)
 In this example, the
		  path to a user mailbox is
		  M:\
domain.com\mbx\
username
		  (in other words, M:\RHS\mbx\LHS). 
 Because the Exchange path points
		  to M:\RHS\mbx, the full path to an item in the inbox is
		  http://server/exchange/LHS/Inbox/item.eml
 By default, user SMTP
		  addresses are
		  
alias@
recipientpolicy.com.
		  M:\RHS\mbx\LHS maps to a unique user object's mailbox and is always
		  addressable.
 To test this, start the Active Directory Users and
		  Computers snap-in, and then add a random, unique SMTP LHS address to a user
		  object that you can access in drive M. For example, add UserA@microsoft.com to
		  the Administrator account administrator@microsoft.com. Then, open a command
		  prompt, go to the M: drive, and then type 
CD RHS\mbx\LHS
		  of the secondary SMTP proxy you just added. In other words, log on to the
		  server as the administrator and type 
CD
		  microsoft.com\mbx\UserA. Note that you see the contents of the
		  administrator account mailbox, even though you did not type that primary SMTP
		  proxy address.
 If you type
		  
http://server/exchange in the address bar of a browser,
		  you are prompted for credentials. After you have supplied credentials, you see
		  an HTML frames page that contains a left frame that has the source
		  http://server/exchange/rhs/?cmd=navbar and a right frame that has the source
		  http://server/exchange/rhs/inbox/?cmd=contents. The end user does not have to
		  know more than the Exchange path (and even less if the URL is set as an
		  Internet Explorer (IE) favorite or presented as a hotlink on a corporate Web
		  page).
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
293386�
                            
 HTTP 401 or 404 error messages when you access OWA implicitly or explicitly
 The
 domain.com
		  is actually based on the default recipient policy. 
		   For additional information, click the
			 following article number to view the article in the Microsoft Knowledge Base: 
259589�
                            
 XADM: How Installable File System Generates the Domain Name