Explicit gateways are not a good idea, generally speaking, because they
don't let the users send commands to the server. [log in to unmask] may
not be the same as [log in to unmask] - it could be [log in to unmask], or
[log in to unmask], or [log in to unmask] at the local site, etc. The problem
is that internet mail from SUVM doesn't work any more; this is a serious
problem, and it should be fixed, not bypassed through another box which
happens to use different routing.