>Michael,
>
>   LISTSERV does use the mailer from DOMAIN NAMES. LISTSERV applies a
>strict interpretation of the file, in that it expects the :nick to be
>a complete domain string. Your entry says:
>
>------------------ Start of included file DOMAIN   NAMES
>-----------------
>:nick.BU.EDU        :mailer.MAILER@BOSTONU    BSMTP  3
>:site.Boston University Local Area Network
>:gatemast.Gatemast@Bostonu
>------------------ End   of included file DOMAIN   NAMES
>-----------------
>LISTSERV interprets this as only applying to node BU.EDU, not to xx.BU.EDU.
>This is also the case with MAILER, I believe. You shoould correct the entry
>to start ":nick..BU.EDU", as do most others in DOMAIN NAMES.
>
>Ross Patterson
>Rutgers University
 
Whoa!  With MAILER it is different!  ":nick..BU.EDU" would indeed pick up
[log in to unmask], but not [log in to unmask] without subdomain.  ":nick.BU.EDU" would
pick up both of the above.  Unfortunately, it would also pick up mail to
any address ending in BU.EDU, even those like [log in to unmask], which is not
part of the BU.EDU domain.  This is a design fault in MAILER.
 
In the domain naming scheme, text-string matching is meaningless.
Addresses must be matched with domains with strict breaks at periods.
Given this, the only reasonable difference in interpretation between
":nick.BU.EDU" and ":nick..BU.EDU" is that the first will accept the
BU.EDU domain as an address without any subdomain, while the second
will not.  If that distinction is not to be allowed, there is no reason
for allowing the form with the leading dot, but the form without it
should always be acceptable.
 
Both MAILER and LISTSERV (and any other users of DOMAIN NAMES) should
be coded so that either form is acceptable and each will accept any
subdomain of the given domain, but no textually similar address which
is not part of the given domain.
 
It *IS* a requirement that mail to the domain itself be allowed in
some cases.  Interpretations which disallow this are unacceptable.
 
If it is a requirement to distinguish between proper subdomains and the
listed domain itself, that distinction can be made be the presence or
absence of the leading period.  The top-level domains may well require
this distinction.  (Is mail to xx@EDU meaningfull?)
 
Please forgive me for flaming.  This is a sore point with me.
 
Mark R. Williamson
Rice University