On Wed, Sep 02, 2015 at 10:47:21AM -0400, Chris Siebenmann wrote:
> > * Why can't the configuration start from an empty file?
>
> Various people will have various answers, but my answer is that it
> doesn't because Exim is a mailer construction kit. It is not doing
> anything when you start it with an empty configuration file for the
> same reason that a construction firm is not going to do anything if
Some MTAs do work with empty configuration files, but the default
behaviour is rarely sufficient as-is, so most administrators do
end up with at least some explicit settings.
The main benefit of supporting "empty" configurations, is that one
need not explicitly configure default/boilerplate settings, so that
the only settings in the configuration file are explicit customizations.
That way the user does not end up "freezing" default settings that
change over time, and can easily see how his system differs from
a stock configuration.
Note, that e.g. in Postfix, while "main.cf" can be empty, "master.cf"
cannot. Sometimes we need to be careful to define what "empty"
means.
--
Viktor.
