Re: [exim] newbie - where to make config changes (on debian,…

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Auteur: Jason Meers
Datum:  
Aan: hblists, dls
CC: exim-users
Onderwerp: Re: [exim] newbie - where to make config changes (on debian, for cyrus+exim)
Hi,

I'm currently writing a beginners guide for Exim which will hopefully be
ready for publishing by the end of the year.

Whilst writing the book the Debian team (Marc Haber especially) have
been very helpful providing information for Debian and Ubuntu sections
the book.

I hope the following excerpts are useful

Basically,

If /etc/exim4/exim4.conf does NOT exist:
The more powerful debconf driven auto-config will be used
The Debian team have their own mailing lists for this

If /etc/exim4/exim4.conf does exist:
A "standard" exim type configuration will be used.
This type of config file is shown in most exim examples.


Thanks

Jason Meers

----


Default MTA
~~~~~~~~~~~
Exim has been Debian's default MTA since 1998.


Installing Exim
~~~~~~~~~~~~~~~
Debian woody (stable until June 2005) installs exim 3 (from the
package named "exim") by default. Since exim 4 and Debian woody are
obsolete, this is not covered any more by this publication.

Debian sarge (stable since June 2005) installs exim 4.50 (from the
package exim4-daemon-light, after pulling in its dependencies
exim4-base and exim4-config). Exim 3 still ships with sarge to allow
for easier updates.

On a system with a different or no MTA installed, you can install Exim
using the Debian package management tools, with Aptitude being the
tool with best support.

Debian offers two packages containing an Exim daemon. While
exim4-daemon-light comes with only basic features (including support
for TLS encryption and the dlopen patch to allow dynamic loading of a
local_scan function) enabled, exim4-daemon-heavy includes LDAP,
PostgreSQL and MySQL data lookups, SASL and SPA SMTP authencation,
embedded Perl interpreter, and exiscan-acl for integration of
virus-scanners and spamassassin in addition to the features already
included in the light daemon. The source package has infrastructure to
easily build a local daemon flavour which conforms to your local needs.

After installation, the packaging system will ask a few questions
about how to configure the package and then create a configuration
that will be useable in the majority of today's e-mail scenarios.


Setting Exim as the default MTA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Debian's dependency management system only allows one packaged MTA to be
installed. So Exim will become default MTA automatically after being
installed.

You can make the Exim Monitor program launch at startup, using the
mechanisms of the X desktop and/or window manager that you have
selected. [The procedure you have cited in the PDF will only work on a
tiny fraction of installed systems since Debian doesn't have a default
desktop].


Location of Exim Binaries
~~~~~~~~~~~~~~~~~~~~~~~~~

/usr/sbin. To minimize conflict potential with the Exim 3 packages,
the binary is called exim4 instead of exim.


Name of Config File
~~~~~~~~~~~~~~~~~~~
The Debconf-driven configuration scheme will place an autogenerated
configuration in /var/lib/exim4/config.autogenerated. If you decide to
use a more conservative approach to exim configuration,
a configuration placed into /etc/exim4/exim4.conf will take precedence
over the auto-generated configuration.


Usual Permissions required on Exim Binaries
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
owner: root, group: root, permissions: 4755 (suid root)


Usual Permissions required on Config Files
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Default, unchanged.


Usual Spool Directory
~~~~~~~~~~~~~~~~~~~~~
/var/spool/exim4


Usual Queue Directory
~~~~~~~~~~~~~~~~~~~~~
/var/spool/exim4/input


Usual Logfile Directory
~~~~~~~~~~~~~~~~~~~~~~~
/var/log/exim4


Starting and stoppin Exim
~~~~~~~~~~~~~~~~~~~~~~~~~
/etc/init.d/exim4 start
/etc/init.d/exim4 stop
/etc/init.d/exim4 restart

The start options will automatically rebuild the autogenerated config.


Default queue settings
~~~~~~~~~~~~~~~~~~~~~~
Configuration of daemons started takes place in /etc/default/exim4.


Misc
~~~~

exim runs as the user Debian-exim.

Debian's exim 4 packages have their own home page on
http://pkg-exim4.alioth.debian.org/, and there is a user-level mailing
list available to cover Debian-related questions about exim like
issues with the Debconf-driven configuration scheme. The package
contains extensive documentation in the man pages for the tools we
deliver, and a multi-hundred line Debian-specific README is delivered as
/usr/share/doc/exim4-base/README.Debian.gz.


Insider Information
~~~~~~~~~~~~~~~~~~~
Debian, the universal operating system, is a project maintained by
volunteers. As a Distribution, we distribute pre-built binary
packages. New packages are uploaded into the "unstable" distribution
(codename "sid"), and migrate to the "testing" distribution (codename
"etch" at the time of this writing) if they have proven sufficiently
bug-free for some time and their dependencies are satisfied. Once in a
while, "testing" is promoted to "stable" and finally released. At the
time of this writing, Debian "stable" has the codename "sarge".

Our configuration frontend "Debconf" is used to ask the user for
information needed to correctly configure a package to work. Debian's
exim 4 packages use Debconf quite extensively and can deliver a
working configuration with quite some bells and whistles
automatically. The configuration scheme suggested by the Debian exim 4
packages seems quite confusing for an Exim expert, but is worth
considering.

The configuration file handling mechanism offered by our package
management preserves local changes to configuration files across
upgrades and gracefully handles conflicts. Feel free to change any
configuration file you feel like changing.

Debian's exim 4 packages use GnuTLS instead of openssl to allow for TLS.

The answers given by the local user on package installation are
used by our central configuration script update-exim4.conf to generate
the actual config file for exim, /var/lib/exim4/config.autogenerated.
Source for the configuration is either a monolithic
/etc/exim4/exim4.conf.template, or a split configuration directory of
configuration snippets, /etc/exim4/conf.d. Which of the two sources is
used is controlled by a Debconf setting as well. Details of this
configuration scheme are documented in the manpage for
update-exim4.conf and accompanying programs, and in
/usr/share/doc/exim4-base/README.Debian.gz. That file also contains a
few comments about updating from exim 3.



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