Fedora Servers :: Multiple Domains With Postfix

I have Postfix + Unix Accounts + Virtual Domains. I have a bunch of domains hosted on my machine, let's call them [URL] [URL] and [URL]... etc Until know, domain2.com, domain3.com were mapped in virtual domains to [URL] So this is how /etc/postfix/virtual looks like:

[URL]

Like I said, all mail accounts are unix accounts, so, if for example I have the user "paul" this user will receive e-mail for ALL DOMAINS. [URL]But as it turns out, I now need a COMPLETELY ISOLATED domain... let's call it [URL]. So If I create a new user, let's call it "steve" I want steve to receive e-mail ONLY on [URL] and not on all others.

I would have to redo the whole thing from the beginning. I'd have to comment out the $mydestination parameter in the main.cf file and start using only virtual domains. So if I have the following users: paul, steve, sally, megan, jenny and I want paul and steve to ONLY receive mail for domain1.com, sally and megan to receive mail for domain2.com and jenny to receive mail for domainX.com, my /etc/postfix/virtual file would have to look like this:

[URL]

I'd have to create the unix account and then start modifying the /etc/postfix/virtual file.