Try to logon and write L F at the @ - prompt.
Then you will get an overview picture og the allowed and used mailboxes, if the F/W of your VMX-200 is higher that S.1 / S.2.
For release L.7.1.5 (and lover) go to update by pressing U (from the @-prompt), write "l user" at the .-prompt. then you will get a full list of users.
Let me know about your success.
///doktor