switches should be set to all up (not sure if that's all on or off)

older vms/fms default is nec no password

only on the newer fms/vms/cms/vmp do you use the support/voice

you will see the banner screen if you can connect.

if nec doesn't work try log in in as all the mailboxes (9+ext) and use their passwords to see if someone else has manager status.