Start up xemacs. M-x gnuserv-start. M-x vm. inbox and inbox
buffers are now displayed.
gnuclient -nw. C-x b *scratch* RET. M-x vm.
Only "N messages, M new, ..." is displayed in the minibuffer of the
gnuclient frame, the vm buffers do not become visible.
I think this is correct behavior, at least as documented.
(setq vm-search-other-frames nil) to change it.