RE: FW: postfix and root dns zones

Bennett,
Many thanks for your time and cogent answer.
Much appreciated.

Matt

-----Original Message-----
From: Bennett Todd [mailto:bet@rahul.net]
Sent: 26 February 2004 15:58
To: Matt Taylor
Cc: 'postfix-users@postfix.org'
Subject: Re: FW: postfix and root dns zones


2004-02-26T10:25:58 Matt Taylor:
> After setting up my dns (correctly?!?) but without having postfix
> 'involved' mail flow between the 2 exchange servers is fine.
>
> By adding postfix into the equation and letting that do the relaying
> mail gets queued at the postfix box UNTIL I make my dns server a root
> server, effectively adding a '.' zone.

This doesn't surprise me. Exchange is only sort of an email system, and
Microsoft is not, shall we say, famous for understanding and correctly
implementing internet standards. No doubt Exchange can work without any DNS
at all.

Postfix, on the other hand, is an internet MTA; DNS is the name service used
for email routing, period.

Postfix doesn't particularly care about root zones as such; it just wants
working DNS. For each domain it's trying to route to, it wants to be able to
do MX lookups for the bits on the right side of the "@" in the address. This
can be suppressed; you can hardwire routing into the transport table, and
that might suffice for a simple lab setup where postfix simply stands
between two other servers.

But if you don't want to do that, you need to have working DNS. Working DNS
almost requires a root zone. It's certainly simplest and best for you to
create one.

If for some reason you want to see how it can work without it, you can
arrange for your recursive resolver to explicitly forward every zone you
need to have to a content server authoritative for that zone. It's icky, but
possible.

-Bennett