Question : Send from Multiple Domain Emails (One Exchange Mailbox)

Hello,

We have an Exchange 2003 server set up with multiple email addresses for each exchange mailbox.  What we want to do is to be able to send from these multiple email addresses separately, but only use a single exchange mailbox.  How exactly can we go about doing this?  

I was attempting to test this on an exchange 2007 server, but even though I can receive emails to these multiple domains & have them all end up in the same place (my exchange mailbox), when I attempt to send from an address other than my primary SMTP address, I get a message back saying I don't have a send as permission.

 I really want to avoid using multiple user accounts (and therefore multiple mailboxes), as you cannot see these in OWA, only in Outlook where you configure them.  Any ideas would be greatly appreciated, thanks.

Answer : Send from Multiple Domain Emails (One Exchange Mailbox)

I know that.. i meant : If you find a way o do it without create multiple mailboxes.....
Yes and no : with OWA you can access othe mailboxes, but you will have to type the entire mailbox path, once connected to your mailbox :
http://www.msexchange.org/tutorials/OWA-2003-End-User-Tips.html