I'm having trouble configuring Exim 4 on a Debian system. How does /etc/exim4/conf.d work?

The Debian Exim 4 packages use a quite uncommon, but elegant, method of configuration where the real Exim configuration file is assembled from a tree of snippets by a script invoked just before the daemon is started (see 9608). This fits very well into the Debian system of configuration file management and is a great ease for the automatic configuration with Debconf. However, it is very different from the normal way Exim 4 is configured. Non-Debian users on the Exim mailing list will probably have difficulty in trying to answer specific questions about it. You may have to find a Debian expert.

One place that you may potentially find information is the extensive documentation which comes with the Debian Exim 4 packages. Possible starting points are

• the README file on your system, /usr/share/doc/exim4-base/README.Debian.gz
• the Wiki page of the Debian Exim 4 packages, https://wiki.debian.org/PkgExim4

An additional place that you may potentially find interesting is the Debian mailing list on Alioth. Note that although this is an Exim4 users list you will probably be speaking with developers and package maintainers who are, in my experience, disinclined to help those who have not already tried to help themselves or clearly show that they have not bothered to read the documentation.

List information is available on the Debian Exim 4 wiki page.