Nick Tait:
> Hi list.
>
> A couple of months ago an email I sent from my phone was bounced by the
> recipient's SMTP server because the email had no Message-ID header. It
> turns out the email app that I've been using on my phone for years
> doesn't generate a Message-ID, but this was the first time that this had
> been a problem...
Then that recipient will lose some portion of their email, because
the email RFCs do NOT require a Message-ID.
> Anyway it turned out to be fairly simple to get Postfix to add the
> missing Message-ID header: I just needed the email to satisfy
> "local_header_rewrite_clients".
This will break valid DKIM signatures when you change the setting
to match arbitrary senders.
> But this got me thinking about 'best practice' configuration of Postfix
> to meet RFC 6409, and I realised that (AFAICT) this isn't covered by the
> Postfix documentation. And so I assume that most people (like me) just
> uncomment the submission lines (in master.cf) provided by their distro's
> postfix package? But this Message-ID experience has shown me that the
> distro's master.cf submission, while good, is not 100% perfect?
There is no perfect defense against idiot system adminstrators.
Trying to enumerate all their mistakes is pointless. There is
no limit to human fallability.
Wietse
