still more forwarding hosts

[MILLER@VAX.CAM.NBS.GOV]

    The Symbolics mail utilities support the syntax
    user_name%host.domain@forwarding-host to do what you've asked.  We
    use this all the time.

     -- Chuck Fry
       Symbolics Software Support

Sounds plausible, but when I test it by sending a message to me on my
sun account (fs1; which forwards eventually back to me at my symbolics)
   miller%fs1.cam.nbs.gov@camvax
I get from postmaster:

Unable to deliver letter to the following recipient:
  miller%fs1.cam.nbs.gov@CAMVAX.nbs.DialNet.Symbolics.COM:
    DNA Mail failed to verify recipient miller%fs1.cam.nbs.gov@CAMVAX.nbs.DialNet.Symbolics.COM.
However, Is the problem with the symbolics or the vax?
Perhaps I should be a bit more explicit about our setup:

  We've got
    1) a few Symbolics (7.2)  talking CHAOS & DNA.
    2) a VAX (CAMVAX) running VMS (4.7) and Excelan's  TCP/IP (EXOS).
    3) a VAX (ENH) running VMS and Wollengong TCP/IP. This machine is
      `directly' connected to internet.
So, our symbolices can only talk to themselves and CAMVAX. CAMVAX can
talk to all local machines (but uses host tables for internet
addresses).

To send email on internet, I telnet to camvax. (if the host is not in
the tables, I've got to forward to ENH; that probably isnt that relevent
right now, but ultimately for some addresses I'll have to forward
through 2 hosts (->camvax->enh) to send email from my symbolics)

So back to the failed mail:  The symbolics obviously sent the message to
camvax who didnt understand it. It may be that the VMS mailer took it
instead of the EXOS daemon (?); the vms mailer certainly would not
understand the address while the exos daemon should.  
Or maybe somebody forgot to change the "%" into a "@"? 
Or what?

So close and yet so far away...
Thanks, Bruce.