I didn't send this because it seemed too obvious, but no one else
mentioned it...
 
Why not just send mail for user@bitnetnode to
[log in to unmask]  Isn't that how people
have been doing it for years?  (For some reason that the CUNY people
probably go bonkers over, cunyvm.cuny.edu seems to be a favourite
machine to do this with.)
 
E.g., if I want to send e-mail to [log in to unmask] (and I don't know
that the Internet equivalent is [log in to unmask]), I could use
[log in to unmask]
 
Yes, it's a hybrid address and may involve an extra step or two (all of
which are offensive to purists and the like), but I do believe it works
rather reliably.
 
Shahrukh Merchant