Zmailer/netfind problem

[davecb@nexus.yorku.ca]

  For people on the zmailer list, netfind is a search service for
email adresses, invented by Mike Schwartz. To quote from the paper:

	We have built a prototype tool that provides a
        simple Internet "white pages" directory  facility.   Given  the
        name  of a user and a rough description of where the user works
        e.g., the company name or city), the tool attempts  to  locate
	telephone  and  electronic mailbox information about that user.
        Measurements indicate  that  the  scope  of  the  directory  is
        upwards of 1,147,000 users in 1,929 administrative domains, yet
        the tool does not require the type of global  cooperation  that
        many  existing  or proposed directory services require
	[...]
        information  formats  is difficult to achieve.  At present, the
        tool utilizes information from USENET news messages, the Domain
        Naming  System,  the  Simple  Mail  Transfer  Protocol, and the
        "finger" protocol,


  One of of the things it does is use smtp EXPN to find presence and forwarding
information for users on a given host.  As the FAQ warns,

        4.  Make sure your Simple Mail Transfer Protocol (SMTP) server on
            each domain-alias host responds correctly to EXPN requests.
            This means
                a. it finds the mail forwarding information, and preferably
                   reports it in a full format (preferably "250 UserName
                   <ForwardingAddress>", rather than "250
                   <ForwardingAddress>")
                b. it doesn't lie when asked a question it doesn't know
                   (e.g., always responding that mail for the specified
                   person is received locally, even if the person doesn't
                   exist; some sites do this to preserve privacy)

  Alas, my copy of zmailer gives ``false drops'': it says ``yes'' even when
a usr isn't local. (It does give correct information if the user is local,
has an alias, etc).
   Is this fixed in a later release?  I'm running 2.2

    If not, is the following a reasonable change?
When I look at server.cf. I find:

        case $(channel $quad) in
        local)  text=$(login2uid $(user $quad)) # ignore return value
                if text="$(fullname $(user $quad))"; then
                        text="local delivery for $text"
                else
                        text="local delivery for"
                fi
And the only thing I don't grok is login2uid...  To my mind it should\
return the null string for a non-user, and all I need do is change the
message to ``unknown user $text''  

Alas, there's more than just that in the file!  The server infers the right
three-digit code, and how to fix that ain't obvious...

--dave

--dave