Re: [exim] Let the 'postmaster' callout option be damned

On Wed, 2004-08-25 at 00:09 +0100, Tim Jackson wrote:
> Specifically, I do not believe that you can deduce from the fact that you
> are presented with a mail with an envelope sender of <foo@???>,
> that example.com is misconfigured just because you cannot send a DSN
> (specifically) to <postmaster@???>.

I tend to agree. I already reject DSNs to lists, and even to real
addresses such as dwmw2@??? -- the only reason I still accept
them to postmaster@ is to prevent postmaster callouts from failing.

One alternative I've considered but not yet implemented is to reject the
DSN-to-postmaster at DATA time instead of at RCPT time. For reasons we
have to explain quite often, that's hard to implement -- we have to
temporarily reject certain RCPTs if the response after DATA wouldn't be
the same for each.

That would be a local workaround though, not a fix.

> Therefore, I invite reasoned opinions, flames and hate mail (though the
> former is preferred) on the following, likely controversial, items:
>
> 1. <...> I should be forced to accept DSNs for mail I didn't send, even to
> special addresses such as postmaster@.
>
> 2. <...> the "postmaster" callout be made a no-op<...>, removed from the
> manual and deprecated.
>
> 3. <...> a strong warning is placed in the Exim spec cautioning against
> the use of the "postmaster" callout option

Or

4. Postmaster callouts shouldn't use the null sender. They should use
something like postmaster@$primary_hostname instead.

Cue Phil being concerned about callout loops -- and rightly so. And of
course if you're going to do a callout with source 'postmaster@' then
you have to accept a DSN to that address. Perhaps the postmaster callout
should require a source address to be specified? It gets complicated.

--
dwmw2