====================
 Installing IMP 4.2
====================

:Last update:   $Date: 2008/05/06 17:54:05 $
:Revision:      $Revision: 1.57.6.17 $
:Contact:       imp@lists.horde.org

.. contents:: Contents
.. section-numbering::

This document contains instructions for installing the IMP web-based mail
client on your system.

For information on the capabilities and features of IMP, see the file README_
in the top-level directory of the IMP distribution.


Obtaining IMP
=============

IMP can be obtained from the Horde website and FTP server, at

   http://www.horde.org/imp/

   ftp://ftp.horde.org/pub/imp/

Or use the mirror closest to you:

   http://www.horde.org/mirrors.php

Bleeding-edge development versions of IMP are available via CVS; see the file
`horde/docs/HACKING`_ in the Horde distribution, or the website
http://www.horde.org/source/, for information on accessing the Horde CVS
repository.


Prerequisites
=============

To function properly, IMP **requires** the following:

1. A working Horde installation.

   IMP runs within the `Horde Application Framework`_, a set of common tools
   for Web applications written in PHP.  You must install Horde before
   before installing IMP.

   .. Important:: IMP 4.0 requires version 3.0+ of the Horde Framework -
                  earlier versions of Horde will **not** work.

   .. _`Horde Application Framework`: http://www.horde.org/horde/

   The Horde Framework can be obtained from the Horde website and FTP server,
   at

      http://www.horde.org/horde/

      ftp://ftp.horde.org/pub/horde/

   .. Important:: Be sure to have completed all of the steps in the
                  `horde/docs/INSTALL`_ file for the Horde Framework before
                  installing IMP.

   Many of IMP's prerequisites are also Horde prerequisites.

2. The following PHP capabilities:

   a. IMAP and POP3 support ``--with-imap``

      IMP **requires** the PHP imap extension to provide IMAP and/or POP3
      support.  To compile the imap extension, the UW-IMAP c-client libray
      must be present on your system.  For help with compiling the imap
      extension ninto PHP, you can view the PHP imap manual entry:

         http://www.php.net/imap

      Because installation of the imap extension can be a non-trivial matter,
      further configuration help/advice follows.

      The UW-IMAP c-client library is available from

         ftp://ftp.cac.washington.edu/imap/

      The most recent code is normally located in a file named 'imap.tar.Z'.

      After building the c-client library (instructions are at the top of
      the Makefile in the base directory of the UW imap package), you may
      need to rename the compiled library file so the local build system can
      find it.  For example, compilation of c-client results in a file named
      'c-client.a' in the 'c-client' directory.  On Linux (at least) this file
      needs to be renamed or linked to libc-client.a, e.g.:

         ln -s c-client.a libc-client.a

      IMP can use IMAP-SSL and POP3-SSL if available.  SSL support needs to be
      built-in to both the c-client library and the PHP extension (see the
      ``--with-imap-ssl`` configure option to PHP).

      If using TLS or SSL to connect to the IMAP/POP3 server, OpenSSL support
      is **required** in PHP. See `OpenSSL Support`_ below.

      .. Tip:: If you notice strange behavior when running IMP (e.g. blank
               screens when accessing certain messages, blank message bodies)
               you should always try recompiling PHP with a different version
               of c-client.  The different versions of the c-client library and
               PHP do not always work well together, and often all it takes is
               to recompile with a different c-client version and the problems
               will go away.

      .. Tip:: If running the webserver changerooted (i.e. the default setting
               on OpenBSD), you may need additional configuration on your
               system to ensure the c-client library works properly.
               See: `Configuring c-client for changerooted webservers`_

      .. _`Configuring c-client for changerooted webservers`: http://lists.horde.org/archives/imp/Week-of-Mon-20050321/041502.html

   b. File Upload Support

      File upload support is **required** to allow attachments in mail
      composition and to allow various importing features to work (e.g.
      importing PGP or S/MIME keys, importing mbox files).  To enable file
      upload support:

          1. In your php.ini file, the following line **must** be present::

                file_uploads = On

          2. Your temporary upload directory **must** be writable to the user
             the web server is running as.  If you leave the configuration
             option ``upload_tmp_dir`` blank in ``php.ini``, PHP will use the
             default directory compiled into it (normally ``/tmp`` on
             Unix-like systems).

          3. Set the maximum size of the uploaded files via the
             ``upload_max_filesize`` configuration option in ``php.ini``.  For
             example, to allow 5 MB attachments, place the following line in
             your ``php.ini`` file::

                upload_max_filesize = 5M

       If either ``file_uploads`` is turned off, or your temporary upload
       directory is *not* writable by the server, all file upload
       functionality will be disabled by Horde/IMP and will not be available
       to the user.

       See the `File Uploads`_ FAQ entry for further information.

   The following PHP options are **RECOMMENDED** to enable advanced features
   in IMP:

.. _`OpenSSL Support`:

   a. OpenSSL support ``--with-openssl``

      The OpenSSL PHP extension is used by IMP to provide S/MIME support.
      Without the extension, all S/MIME options will be disabled.

      Additionally, the OpenSSL PHP extension is REQUIRED if using TLS or SSL
      to connect to the IMAP/POP3 server.

      See http://www.php.net/openssl for information on compiling OpenSSL
      into PHP.

   b. tidy ``--with-tidy`` (PHP 5+ only)

      The tidy PHP extension is required if you want IMP to sanitize the
      output of HTML messages before displaying to the user and if you want
      to clean and repair outgoing HTML messages composed via the HTML
      composition mode.  See ``imp/config/mime_drivers.php.dist`` for
      further instructions on how to enable this feature.

3. The following PEAR modules:
   (See `horde/docs/INSTALL`_ for instructions on installing PEAR modules)

   a. Auth_SASL [OPTIONAL]

      Auth_SASL is required if your IMAP server uses CRAM-MD5 or DIGEST-MD5
      authentication.

   b. HTTP_Request [OPTIONAL]

      HTTP_Request is used in the HTML composition mode to download remote
      images contained in the message and store them in the body of the
      outgoing messages.  Without HTTP_Request, the message will be sent
      with the images linked to the remote images, with no guarantee that
      the remote images will still be accessible when the recipient of the
      message views that message.

4. The following PECL modules:
   (See `horde/docs/INSTALL`_ for instructions on installing PECL modules)

   a. idn [OPTIONAL]

      idn is required in order to handle Internationalized Domain Names
      (see RFC 3490).

5. At least one IMAP or POP3 server.

   While IMP is an application that is installed on a Web server and is run
   from a Web browser, it is only an IMAP and POP3 *client*, like Outlook,
   Apple Mail or Thunderbird. You must have access to an IMAP or POP3
   server(s) on which your users' mail is stored in order to use IMP.

   IMAP is *strongly* recommended over POP3.  See, e.g.,
   http://www.imap.org/imap.vs.pop.brief.html

   Freely available IMAP servers (for \*nix systems) that have been verified
   to work with IMP include:

   - Courier-IMAP (http://www.inter7.com/courierimap.html)
   - Cyrus (http://asg.web.cmu.edu/cyrus/)
   - Dovecot (http://www.dovecot.org/)
   - UW-IMAP (ftp://ftp.cac.washington.edu/imap/)

The following items are not required, but are strongly **RECOMMENDED**:

1. Sendmail or equivalent.

   While Horde can send mail via either a local sendmail or a remote SMTP
   server, sendmail is recommended for use with IMP for improved performance
   and error handling/reporting, as well as a more accurate mail envelope.

   The mail transport settings are set in the Horde configuration, so further
   documentation can be found there.

2. Turba, the Horde contacts manager.

   Turba is the Horde contact management application, designed to be
   integrated with other Horde applications to provide a unified interface to
   contact management throughout the Horde suite.

   Turba is available from:

      http://www.horde.org/turba/

      ftp://ftp.horde.org/pub/turba/

   Turba provides a local address book and an LDAP directory search function
   to IMP.

   You must use the 2.x branch of Turba with IMP 4.x.

3. Ingo, the Horde mail filters manager.

   Ingo is the Horde mail filters management application, designed to be
   integrated with other Horde applications to provide a unified interface to
   filter management throughout the Horde suite.

   Ingo is available from:

      http://www.horde.org/ingo/

      ftp://ftp.horde.org/pub/ingo/

   Ingo provides the mail filtering interfaces to IMP - there is no built-in
   filtering in IMP.

   You must use the 1.x branch of Ingo with IMP 4.x.

   To use IMAP client-side filtering (i.e. the filtering provided by IMP 3.x),
   ingo should use the ``null`` driver and the ``imap`` script settings (set
   in ``ingo/config/backends.php``).

4. Nag, the Horde tasks manager.

   Nag is the Horde tasks management application, designed to be integrated
   with other Horde applications to provide a unified interface to task
   management throughout the Horde suite.

   Nag is available from:

      http://www.horde.org/nag/

      ftp://ftp.horde.org/pub/nag/

   If nag is available on your system, users can easily create new tasks from
   individual email messages.

   You must use the 2.x branch of Nag with IMP 4.x.

5. Gollem, the Horde file manager.

   Gollem is the Horde file management application, designed to be
   integrated with other Horde applications to provide a unified interface to
   access VFS filesystems throughout the Horde suite.

   Gollem is available from:

      http://www.horde.org/gollem/

      ftp://ftp.horde.org/pub/gollem/

   Gollem allows a user to attach files from various VFS filesystems to
   outgoing messages in IMP.

   You must use the 1.x branch of Gollem with IMP 4.x.

6. aspell - Spelling Checker

   Aspell, a comand-line program, is used as IMP's spell-checking engine.
   You must install and configure aspell to use IMP's spell-check feature.

   Version 0.60 or higher is REQUIRED.

   You can obtain aspell from:

      http://aspell.sourceforge.net/

7. A web server with PATH_INFO support.

   IMP requires a web server that correctly sets the PATH_INFO environment
   variable for all PHP scripts for several features. Every modern web server
   supports this, but you might have to enable this feature in the web server
   configuration. e.g. Apache servers require::

      AcceptPathInfo On

   If the webserver does not provide PATH_INFO information, IMP attempts to
   create the information using other server variables, but this process is
   slower and less reliable.


Installing IMP
==============

IMP is written in PHP, and must be installed in a web-accessible directory.
The precise location of this directory will differ from system to system.
Conventionally, IMP is installed directly underneath Horde in the web server's
document tree.

Since IMP is written in PHP, there is no compilation necessary; simply expand
the distribution where you want it to reside and rename the root directory of
the distribution to whatever you wish to appear in the URL.  For example, with
the Apache web server's default document root of ``/usr/local/apache/htdocs``,
you would type::

   cd /usr/local/apache/htdocs/horde
   tar zxvf /path/to/imp-x.y.z.tar.gz
   mv imp-x.y.z imp

and would then find IMP at the URL::

   http://your-server/horde/imp/


Configuring IMP
===============

1. Configuring Horde for IMP

   a. Register the application

      In ``horde/config/registry.php``, find the ``applications['imp']``
      stanza.  The default settings here should be okay, but you can change
      them if desired.  If you have changed the location of IMP relative to
      Horde, either in the URL, in the filesystem or both, you must update the
      ``fileroot`` and ``webroot`` settings to their correct values.

   b. Enable IMP authentication [OPTIONAL]

      If you would prefer that your users authenticate directly with IMP,
      without having to authenticate through Horde first, load the
      ``Administration/Setup/Authentication`` page and from the ``What backend
      should we use for authenticating users to Horde`` pulldown menu select
      ``Let a Horde application handle authentication``.  (Please see the
      second note below.) Select ``imp`` from the ``The application which is
      providing authentication`` pulldown menu.

      .. Note:: **You will have to log in twice if you don't do this** -- Once
                to Horde and a second time to IMP.

      .. Note:: If this is a new install, you will not be able to configure
                IMP using the Horde Administration/Setup page if you first
                enabled IMP authentication for Horde.  You must set Horde to
                use another authentication method (refer to the
                `horde/docs/INSTALL`_ file), configure IMP, then reset Horde
                to use IMP authentication.  One way to reset Horde in order to
                reach the Administration page is to replace the Horde
                configuration file ``conf.php`` with the original in
                ``horde/config/conf.php.dist``.  You should of course back up
                your current settings since they will otherwise be permanently
                lost.

2. Creating the database table

   The specific steps to create the IMP database table depend on which
   database you've chosen to use.

   First, look in ``scripts/sql/`` to see if a script already exists
   for your database type.  If so, you should be able to simply execute that
   script as superuser in your database.  (Note that executing the script as
   the "horde" user will probably fail when granting privileges.)

   If such a script does not exist, you'll need to build your own, using the
   file imp.sql as a starting point.  If you need assistance in creating
   databases, you may wish to let us know on the IMP mailing list.

3. Configuring IMP

   To configure IMP, change to the ``imp/config/`` directory of the installed
   distribution, and make copies of all of the configuration ``dist`` files
   without the ``dist`` suffix::

      cd config/
      for foo in *.dist; do cp $foo `basename $foo .dist`; done

   Or on Windows::

      copy *.dist *.

   Documentation on the format and purpose of those files can be found in each
   file.  You may edit these files if you wish to customize IMP's appearance
   and behavior.  With the following exceptions, the defaults will be correct
   for most sites.

   a. servers.php

      You must be sure to list your IMAP/POP3 server names and
      configuration information in ``servers.php`` (unless you allow
      users to choose any server).

   b. motd.php

      You should either provide your own message-of-the-day type
      information, or remove motd.php.

   You must login to Horde as a Horde Administrator to finish the
   configuration of IMP.  Use the Horde ``Administration`` menu item to get to
   the administration page, and then click on the ``Setup`` icon to get the
   configuration page.  Select ``Mail`` from the selection list of
   applications.  Fill in or change any configuration values as needed.  When
   done click on ``Generate Mail Configuration`` to generate the ``conf.php``
   file.  If your web server doesn't have write permissions to the IMP
   configuration directory or file, it will not be able to write the file.  In
   this case, go back to ``Setup`` and choose one of the other methods to
   create the configuration file ``imp/config/conf.php``.

   Note for international users: IMP uses GNU gettext to provide local
   translations of text displayed by applications; the translations are found
   in the ``po/`` directory.  If a translation is not yet available for your
   locale (and you wish to create one), see the ``horde/po/README`` file, or
   if you're having trouble using a provided translation, please see the
   `horde/docs/TRANSLATIONS`_ file for instructions.

   IMP Configuration Pointers

   * If you would like IMP to scan all text messages for UUencoded data, you
     must make this change in ``imp/config/mime_drivers.php``::

     $mime_drivers['imp']['plain']['uuencode'] = true;

     Note that this is a performance hit since *every* text body must be
     scanned in its entriety to look for uuencoded data.  Therefore, this
     feature is disabled by default.

   * By default, IMP is configured to NOT display text/html message parts
     inline.  This is done for various security reasons.  If you would like
     to see text/html parts inline, you must make this change in
     ``imp/config/mime_drivers.php``::

     $mime_drivers['imp']['html']['inline'] = true;

4. Securing IMP

   Before you can secure IMP, you need a secure Horde installation.  Please
   read the file in `horde/docs/SECURITY`_ for Horde security information
   before proceeding.

   There are two channels by which, unless steps are taken to avoid it, IMP
   encourages users to pass their IMAP and POP3 passwords around the Internet
   unencrypted.

   The first channel is between their browser and the Web server.  We strongly
   recommend using an SSL-capable Web server to give users the option of
   encrypting communications between their browser and the Web server on which
   IMP is running; some sites may wish to disable non-SSL access entirely.

   The second channel is between the Web server and their IMAP or POP3 server.
   The simplest way to avoid this is to have the mail server running on the
   same system as the Web server, and configuring IMP to connect to the IMAP
   or POP3 server on ``localhost`` instead of on the Internet hostname.  In
   cases where that is not possible, we recommend using IMAP-SSL or POP3-SSL
   to ensure that users' passwords remain safe after they have entrusted them
   to IMP.

   Other security steps you can take to increase security include:

   * Use session cookies instead or URL based sessions.
   * Set your php ``session.entropy_length`` to a larger value (e.g. 16) and
     ``session.entropy_file`` to a random source (e.g. ``/dev/urandom``)
   * Enable and use the php mycrypt extension.
   * If your database, mail server, and web server are on the same host
     machine, then:

     * use unix socket database access and disable tcp database access.
     * use ``localhost`` for all TCP/IP connections to avoid the network.
     * use the command-line sendmail for sending mail if possible.

5. Testing IMP

   Once you have configured IMP, bring up the included test page in your Web
   browser to ensure that all necessary prerequisites have been met.  See the
   `horde/docs/INSTALL`_ document for further details on Horde test
   scripts. If you installed IMP as described above, the URL to the test page
   would be::

      http://your-server/horde/imp/test.php

   The test script will also allow you to test your connection to the mail
   server and provide some auto-detected configuration parameters that can
   then be inserted into the server configuration located in
   ``imp/config/servers.php``.

   Next, use IMP to login to a known working IMAP or POP3 server.  Test at
   least the following:

   - Sending mail (via the ``Compose`` item in the menu bar).
   - Setting preferences (check to see if they survive after logging out and
     back in, if you are using an SQL or LDAP preferences system).
   - Reading mail.
   - Deleting mail.
   - Flagging mail (if using IMAP).
   - Changing folders (if using IMAP).

6. Tuning IMP (Performance)

   See `horde/docs/PERFORMANCE`_.

   IMP Specific Performance Information

   As of IMP 4.2, IMP can now use persistent caching on the server side to
   store information about user's messages.  This results in much reduced
   IMAP server traffic and requires the server to parse the structure of every
   message only once.  The tradeoff is your cache backend must be able to
   handle the potentially large amounts of cached data this option will
   produce.

   To use this caching, you must have a ``Cache System`` configured in Horde's
   ``Administration/Setup`` screen and have the relevant settings enabled in
   IMP's setup screen (``Administration/Setup/Webmail/Mailbox and Fetchmail``.


Obtaining Support
=================

If you encounter problems with IMP, help is available!

The Horde Frequently Asked Questions List (FAQ), available on the Web at

  http://www.horde.org/faq/

The Horde Project runs a number of mailing lists, for individual applications
and for issues relating to the project as a whole.  Information, archives, and
subscription information can be found at

  http://www.horde.org/mail/

Lastly, Horde developers, contributors and users may also be found on IRC,
on the channel #horde on the Freenode Network (irc.freenode.net).

Please keep in mind that IMP is free software written by volunteers.  For
information on reasonable support expectations, please read

  http://www.horde.org/support.php

Thanks for using IMP!

The IMP team


.. _README: ?f=README.html
.. _`horde/docs/HACKING`: ../../horde/docs/?f=HACKING.html
.. _`horde/docs/INSTALL`: ../../horde/docs/?f=INSTALL.html
.. _`horde/docs/PERFORMANCE`: ../../horde/docs/?f=PERFORMANCE.html
.. _`horde/docs/SECURITY`: ../../horde/docs/?f=SECURITY.html
.. _`horde/docs/TRANSLATIONS`: ../../horde/docs/?f=TRANSLATIONS.html
.. _`File Uploads`: http://wiki.horde.org/FAQ/Admin/FileUploads