Qmailadmin with /etc/passwd domain

[Mike Hodson]

Is it possible to use qmailadmin on a 'default' domain of /etc/passwd
authenticated users?  Currently I provide shells to various users, and they
all need pop3 email access. However, I also want to use qmailadmin to
configure and set-up ezmlm on that same host (mystica.cx) as well as
ezmlm/vpopmail on sub-hosts and different domains entirely
(thing1.mystica.cx, some.other.com)

If this can work, please let me know how. 
If not, then what are my other options?

Thanks 
Mike