Re: message-Id has localhost

[Ken Hornstein]

>> [...] Sendmail,
>> yes, it looks like you could change it if you really want to; it also
>> defaults to something based on the local hostname.  I am personally
>> skeptical that people actually configure this.
>>
>
>FWIW, MIT's campus computer network (Athena) did this for a long time,
>because that network was composed of thousands of workstations that did not
>normally receive mail and all wanted to send mail that came from, for
>example, <yandros@mit.edu> rather than something like <
>yandros@w20-575-77.mit.edu>.

What you're talking about is a very common way of configuring Sendmail
and I've personally done that many times; I call that a "site"
configuration where all email that is submitted to the main Sendmail
server with an internal hostname (or no hostname) is re-written to have
the 'site' domain name.

But what I was specifically talking about was that I am skeptical that
anyone specifically configures a Message-ID header to be added by sendmail
that is different than the default, which is based on the 'j' macro.

I just looked in my wife's Sendmail 'bat' book and it says j holds the
FQDN of the local machine, which probably means it does something similar
to what nmh does; you can override that value if Sendmail gets it
wrong, _HOWEVER_ it's used by a bunch of things and not just for
Message-ID generation.  So to one of Ralph's earlier points, it seems
like we are using some MTA prior art, it just that it doesn't work for
everybody.

--Ken