>> [...] 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, <yand...@mit.edu> rather than something like < >yand...@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