Re: Can we please refuse mail to the list from list addresses?

On Thu, Nov 29, 2007 at 09:25:48AM -0300, Alvaro Herrera wrote:
> 
> Hmm.  Suppose I'm using the mutt MUA, and I have a Postfix instance
> running in my local machine.  So mutt does submission to Postfix
> locally, and Postfix delivers to the MTA that my company has set up for
> me.
> 
> What port should my local Postfix use to deliver to my company's email
> server?

Ideally, the submit port.  But if you have a completely controlled network,
smtp is ok.  That's the idea.

> With Magnus proposal to ban email from @postgresql.org addresses that
> wasn't delivered through mail.postgresql.org, I would not be allowed to
> use my local Postfix server.  Instead I would have to configure mutt to

No, this is not part of that BCP, and I realised (after I sent my note) that
we were talking about two different things.  The idea is that your mail
server authenticates _you_, and also that it authenticates what domains
you're going to send from, which means that it is willing to pass along mail
From: those domains.  The latter is complicated, and will be made worse by
signing tricks.

There is something to be said for rejecting mail from users that are not
subscribed, and that also are not authenticated anywhere in their relay
series.  

But as Marc noted (and sorry I didn't reply yesterday.  Server issues here
again -- I never really fixed things properly, as I haven't had time, so it
serves me right -- prevented me reading mail yesterday) I wasn't advocating
that; what I was suggesting was simply rejecting mail to the list from the
list address itself.  This is a list manager trick.

A

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Andrew Sullivan
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