cvm-testclient newbie question

Please forgive my newbie question here, but I have been banging my head
against a wall trying to figure this out.  Basically, I want to
implement mailfront to do smtp authentication for postfix.  Obviously,
cvm is a necessary component.  I am having considerable trouble with
cvm.  I see the syntax claims the following: 

cvm-testclient cvmodule account domain [credential [credential ...]]

What is the appropriate syntax to use one of the cvm binaries to
authenticate against the unix /etc/passwd file?  Every possible
combination of variables I try leaves me with one of two possible
responses

usage: cvm-testclient cvmodule account domain [credential
[credential ...]]

or

Authentication failed, error #1

Best Regards,

Richard Blalock