Using one mailbox at ISP for many people

[Jonathan Matthews <jaycee.removeifnotspam@jaycee.uklinux.net>]

Hi all

[BRIEF SUMMARY - How do I segregate one mail stream from one mailbox 
at my ISP into different users locally?]

At the moment, I'm the only person using my machine.  However, having 
installed the GNOME 2.2 backport, I've finally got a desktop that I feel 
happy in sitting my SO down in front of and not worrying that she'll 
find it so confusing that she runs screaming from the room.  Yes, she's 
not the most technical of sorts, but she tries hard :-)

I'm trying to set her up using, for the sake of simplicity and general 
"nicely-integrated" reasons, balsa as her MUA.

She's been using mail.com for a web-based account for a while, but it 
sucks (slow AND featureless).  I'd like to get her up and running with 
my machine, and using my email ISP.

I receive all email to <anything>@jaycee.uklinux.net.  I'd like her to 
have a specific one at that domain.  For the benefit of any 
bottom-feeders harvesting the archives, let's say she's going to get 
spammenow@jaycee.uklinux.net. :-)

The problem is that I get only one actual physical mailbox at 
uklinux.net, and all email to @jaycee.uklinux.net gets delivered to it.  
The username it's sent to /is/ preserved in the headers, however.

What combination of programs do I use to get one mailbox successfully 
segregated when it hits my machine?  I'm using fetchmail -> exim -> 
procmail at the moment, but I've lurked on the procmail list long enough 
not to ask about using it as a MDA (or is it an MTA that it shouldn't 
be treated as?).

Any help gratefully received and appreciated.

-- jc
-- 
$ cat .me/contactdetails/home
[listmail]
$ cat .me/contactdetails/work
[listmail]