In his letter, Valdis states:
 
>I think the way we ended up with headers of the form "@ node" <user>
>is that it got '@node:userid' as the address.
>Probably, some site used [log in to unmask]:IBM-Nets%bitnic.bitnet'
>as the address.  I am told that this *IS* legal syntax, but I can't remember
>whether it is RFC822 or RFC733 that allows this flake.  I know that *I*
>sure don't like it.
>
>Ah, for a fully RFC822, full-domain world.
>
>                                   Valdis Kletnieks
 
Ah, but Valdis, think of all of us UNIX hacks that can't connect
to everybody, and therefore use @machine-who-can-connect: as a
transport to the 'fully RFC822, full-domain world'... 8-)
 
Anyway, I think that the @host:user%node is very easy to parse, all
you have to do is look at the first thing after the @ sign and go from
there..
 
-abc