> >It's WA that has access to the list header.
>
> WA does NOT have access to the list header. On unix this may be
> the case because it is suid listserv due to various issues with web
> servers executing scripts as 'nobody' and so on, but it is not part of
> the design of WA and is not the case on other systems where it runs
> as a normal non-privileged user.
>
>   Eric
>

Well, I over-simplified.  WA could access a file created in the web
directory from information in the list header and a configuration file
specifying correspondence between service domains and IP addresses.
That file could contain the access restrictions for the list.  It could
be created at some appropriate time (it wouldn't have to be immediate).