Linux Network Administratoramp;#039;s Guide (3rd Edition) [Electronic resources] نسخه متنی

15.2. Cyrus IMAP

Another
option IMAP administrators have is the product from CMU called Cyrus.
It is similar to UW IMAP as far as general functionality
goesfrom the user standpoint, there will be little difference.
The majority of the differences come on the administrative side. This
is also where its benefits can be seen.

15.2.1. Getting Cyrus IMAP

The Cyrus software can be obtained in a number of places, but the
most reliable choice, with the latest source releases, will be the
central CMU Cyrus distribution site, http://asg.web.cmu.edu/cyrus/download/. Here,
both current and previous releases can be downloaded. The
availability of previous releases could be an advantage for sites
with polices against using the most recent versions of software.

To begin the installation of the Cyrus server, download and
decompress the latest version. You will need to download both the
IMAP and SASL packages.

SASL is the authentication mechanism
used by Cyrus IMAP, and will need to be configured and installed
first. It is easily built using the standard
"configure-make" order.

vlager# cd cyrus-sasl-2.1.15 
vlager# ./configure 
loading cache ./config.cache
checking host system type... i686-pc-linux-gnu
.
creating saslauthd.h
Configuration Complete. Type 'make' to build.
vlager# make 
make  all-recursive
make[1]: Entering directory `/tmp/cyrus-sasl-2.1.15'

Assuming the compile is completed without failure and
you've successfully executed the make install, you
can now proceed to configuring and installing the Cyrus IMAP server
itself.

After decompressing the Cyrus IMAP source, prepare the configuration
using the following command:

vlager# ./configure --with-auth=unix

This will prepare Cyrus IMAP to use
the Unix passwd/shadow files for user
authentication. It is also possible to enable Kerberos for
authentication at this point.

Next, you will need to create all of the dependency files, and then
build and install the package:

vlager# make depend
. . . 
vlager# make all CFLAGS=-O
. . . 
vlager# make install 
. . .

With that successfully completed, your Cyrus IMAP server is now ready
to be configured.

15.2.2. Configuring Cyrus IMAP

You will need to create a user for the Cyrus server to use. It should
be something that you can easily relate to your Cyrus server, and it
also needs to be a part of the mail group.

Once the
user is created, you can begin configuring your Cyrus server. The
/etc/imapd.conf file is the primary
configuration file for the server. Verify that it looks something
like the example below. You may need to add some of these lines.

configdirectory:        /var/imap
partition-default:      /var/spool/imap
sievedir:               /var/imap/sieve
# Don't use an everyday user as admin.
admins:                 cyrus root
hashimapspool:          yes
allowanonymouslogin:    no
allowplaintext:         no

15.2.3. Troubleshooting Cyrus IMAP

Building Cyrus IMAP can be somewhat
tricky, as it tends to be pickier about files and locations. If the
configure process is failing, take special note of what exactly is
causing the failure. For example, when building Cyrus-SASL, if the
build fails with an error complaining about undefined references in
the berkeley_db section, it is likely that you do
not have BerkeleyDB installed, or you installed it in a place where
the configure script isn't looking. The path to the
installed BerkeleyDB can be set at the command line when the
configure script is run. This method of tracing the root of the
error, and remedying it can solve many problems.

Another
common problem when building Cyrus IMAP involves the location of a
file called com_err.h. It is expected by Cyrus
IMAP to be in the /usr/include directory.
However, it often tends to be found in the
/usr/include/et directory. Therefore, it will be
necessary to copy this file to the /usr/include
directory for the installation to proceed.