[BNM] ubuntu - courier IMAP

[Joe Aliferis]

Could anyone help me out...

I have a client with an ubuntu server (6.1) running courier / exim

They asked me as a favour, to create a new IMAP mail user for them.

I have ssh terminal access and root passwd

Can anyone tell me how to create a new IMAP user for Courier using the 
command line?

I've had a look about and the current UNIX users in /home/username  all 
appear to have a Maildir directory with 3 directories inside:

cur
new
tmp

Much appreciated

Joe