[offlineimap] / offlineimap / head / offlineimap.sgml

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  <!ENTITY OfflineIMAP "<application>OfflineIMAP</application>">
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<reference>
  <title>OfflineIMAP Manual</title>

  <refentry>
    <refentryinfo>
      <address><email>jgoerzen@complete.org</email></address>
      <author><firstname>John</firstname><surname>Goerzen</surname></author>
      <date> $Date: 2003-01-08 10:12:49 -0600 (Wed, 08 Jan 2003) $ </date>
    </refentryinfo>

    <refmeta>
      <refentrytitle>offlineimap</refentrytitle>
      <manvolnum>1</manvolnum>
      <refmiscinfo>John Goerzen</refmiscinfo>
    </refmeta>

    <refnamediv>
      <refname>OfflineIMAP</refname>
      <refpurpose>Powerful IMAP/Maildir synchronization
        and reader support</refpurpose>
    </refnamediv>

    <refsynopsisdiv>
      <cmdsynopsis>
        <command>offlineimap</command>
        <arg>-1</arg>
        <arg>-P <replaceable>profiledir</replaceable></arg>
        <arg>-a <replaceable>accountlist</replaceable></arg>
        <arg>-c <replaceable>configfile</replaceable></arg>
        <arg>-d <replaceable>debugtype[,...]</replaceable></arg>
        <arg>-o</arg>
        <arg>-u <replaceable>interface</replaceable></arg>
      </cmdsynopsis>
      <cmdsynopsis>
        <command>offlineimap</command>
        <group choice="plain"><arg>-h</arg><arg>--help</arg></group>
      </cmdsynopsis>
    </refsynopsisdiv>

    <refsect1>
      <title>Description</title>

      <para>&OfflineIMAP; is  a  tool  to  simplify  your  e-mail
        reading.  With &OfflineIMAP;, you can read the same mailbox
        from multiple computers.  You get a current copy of your
        messages on each computer, and changes you make one place will be
        visible on all other systems.  For instance, you can delete a message
        on your home computer, and it will appear deleted on your work
        computer as well.  &OfflineIMAP; is also useful if you want to
        use a mail reader that does not have IMAP support, has poor IMAP
        support, or does not provide disconnected operation.
      </para>

      <para>&OfflineIMAP; is <emphasis>FAST</emphasis>; it synchronizes
        my two accounts with over 50 folders in 3 seconds.  Other
        similar tools might take over a minute, and achieve a
        less-reliable result.  Some mail readers can take over 10
        minutes to do the same thing, and some don't even support it
        at all.  Unlike other mail tools, &OfflineIMAP; features a
        multi-threaded synchronization algorithm that can dramatically
        speed up performance in many situations by synchronizing
        several different things simultaneously.
      </para>

      <para>&OfflineIMAP; is <emphasis>FLEXIBLE</emphasis>; you can
        customize which folders are synced via regular expressions,
        lists, or Python expressions; a versatile and comprehensive
        configuration file is used to control behavior; two user
        interfaces are built-in; fine-tuning of synchronization
        performance is possible; internal or external automation is
        supported; SSL and PREAUTH tunnels are both supported; offline
        (or "unplugged") reading is supported; and esoteric IMAP
        features are supported to ensure compatibility with the widest
        variety of IMAP servers.
      </para>

      <para>&OfflineIMAP; is <emphasis>SAFE</emphasis>; it uses an
        algorithm designed to prevent mail loss at all costs.  Because
        of the design of this algorithm, even programming errors
        should not result in loss of mail.  I am so confident in the
        algorithm that I use my own personal and work accounts for
        testing of &OfflineIMAP; pre-release, development, and beta
        releases.  Of course, legally speaking, &OfflineIMAP; comes
        with no warranty, so I am not responsible if this turns out
        to be wrong.
      </para>

      <refsect2>
        <title>Method of Operation</title>
       
        <para>&OfflineIMAP; operates by maintaining a hierarchy of
          mail folders in Maildir format locally.  Your own mail
          reader will read mail from this tree, and need never know
          that the mail comes from IMAP.  &OfflineIMAP; will detect
          changes to the mail folders on your IMAP server and your own
          computer and bi-directionally synchronize them, copying,
          marking, and deleting messages as necessary.
        </para>
      </refsect2>
    </refsect1>
    
    <refsect1>
      <title>Quick Start</title>
      <para>If you have already installed &OfflineIMAP; system-wide,
        or your system adminstrator has done that for you, your task
        for setting up &OfflineIMAP; for the first time is quite
        simple.  You just need to set up your configuration file, make
        your folder directory, and run it!
      </para>

        <para>You can quickly set up your configuration file.  The distribution
          includes a file <filename>offlineimap.conf.minimal</filename>
          (Debian users
          may find this at
          <filename>/usr/share/doc/offlineimap/examples/offlineimap.conf.minimal</filename>) that is a basic example of setting of &OfflineIMAP;.  You can
          simply copy this file into your home directory and name it
          <filename>.offlineimaprc</filename> (note the leading period).  A
          command such as <command>cp offlineimap.conf.minimal ~/.offlineimaprc</command> will do it.  Or, if you prefer, you can just copy this text to
          <filename>~/.offlineimaprc</filename>:
        </para>

        <PROGRAMLISTING>[general]
accounts = Test

[Test]
localfolders = ~/Test
remotehost = examplehost
remoteuser = jgoerzen
</PROGRAMLISTING>

        <para>Now, edit the <filename>~/.offlineimaprc</filename> file with
          your favorite editor.  All you have to do is specify a directory
          for your folders to be in (on the <property>localfolders</property>
          line), the host name of your IMAP server (on the
          <property>remotehost</property> line), and your login name on
          the remote (on the <property>remoteuser</property> line).  That's
          it!</para>

        <para>To run &OfflineIMAP;, you just have to say
          <command>offlineimap</command> -- it will fire up, ask you for
          a login password if necessary, synchronize your folders, and exit.
          See?  You can just throw away the rest of this finely-crafted,
          perfectly-honed manual!  Of course, if you want to see how you can
          make &OfflineIMAP; FIVE TIMES FASTER FOR JUST $19.95 (err, well,
          $0), you have to read on!
        </para>

    </refsect1>

    <refsect1>
      <title>Installation</title>

      <para>If you are reading this document via the "man" command, it is
        likely
        that you have no installation tasks to perform; your system
        administrator has already installed it.  If you need to install it
        yourself, you have three options: a system-wide installation with
        Debian, system-wide installation with other systems, and a single-user
        installation.  You can download the latest version of &OfflineIMAP; from
        <ulink url="http://quux.org/devel/offlineimap/">the &OfflineIMAP;
        website</ulink>.
      </para>

      <refsect2>
        <title>Prerequisites</title>

        <para>In order to use &OfflineIMAP;, you need to have these conditions
          satisfied:
        </para>

        <itemizedlist>
          <listitem>
            <para>Your mail server must support IMAP.  Most Internet Service
              Providers
              and corporate networks do, and most operating systems
              have an IMAP
              implementation readily available.
            </para>
          </listitem>
          <listitem>
            <para>
              You must have Python version 2.2.1 or above installed.
              If you are
              running on Debian GNU/Linux, this requirement will automatically be
              taken care of for you.  If you do not have Python already, check with
              your system administrator or operating system vendor; or, download it from
              <ulink url="http://www.python.org/">the Python website</ulink>.
              If you intend to use the Tk interface, you must have Tkinter
                (python-tk) installed.  If you intend to use the SSL interface, your
                Python must have been built with SSL support.
            </para>
          </listitem>
          <listitem>
            <para>
              Have a mail reader that supports the Maildir mailbox format.  Most
              modern mail readers have this support built-in, so you can choose from
              a wide variety of mail servers.  This format is also known as the
              "qmail" format, so any mail reader compatible with it will work with
              &OfflineIMAP;.
        </itemizedlist>
      </refsect2>

      <refsect2>
        <title>System-Wide Installation, Debian</title>
        <para>
          If you are tracking Debian unstable, you may install
          &OfflineIMAP; by simply running the following command as root:
        </para>
        <para>
          <command>apt-get install offlineimap</command>
        </para>
        <para>
          If you are not tracking Debian unstable, download the Debian .deb
          package from the <ulink url="http://quux.org/devel/offlineimap/">&OfflineIMAP; website</ulink>
          and then run <command>dpkg -i</command> to install the downloaded
          package.  Then, skip to <xref linkend="configuration" endterm="configuration-title"> below.  You will type <command>offlineimap</command> to
          invoke the program.
        </para>
      </refsect2>

      <refsect2>
        <title>System-Wide Installation, Other</title>
        <para>
          Download the tar.gz version of the package from the
          <ulink url="http://quux.org/devel/offlineimap/">website</ulink>.
          Then run
          these commands, making sure that you are the "root" user first:
        </para>

        <ProgramListing>tar -zxvf offlineimap_x.y.z.tar.gz
cd offlineimap-x.y.z
python2.2 setup.py install</ProgramListing>
        <para>On some systems, you will need to use
          <command>python</command> instead of <command>python2.2</command>.
          Next, proceed to <xref linkend="configuration" endterm="configuration-title"> below.  You will type <command>offlineimap</command> to
          invoke the program.
        </para>
      </refsect2>

      <refsect2>
        <title>Single-Account Installation</title>
        <para>
          Download the tar.gz version of the package from the
          <ulink url="http://quux.org/devel/offlineimap/">website</ulink>.
          Then run these commands:
        </para>

        <ProgramListing>tar -zxvf offlineimap_x.y.z.tar.gz
cd offlineimap-x.y.z</ProgramListing>

        <para>When you want to run &OfflineIMAP;, you will issue the
          <command>cd</command> command as above and then type
          <command>./offlineimap.py</command>; there is no installation
          step necessary.
        </para>
      </refsect2>
    </refsect1>

    <refsect1 id="configuration">
      <title id="configuration-title">Configruation</title>
      <para>
        &OfflineIMAP; is regulated by a configuration file that is normally 
        stored in <filename>~/.offlineimaprc</filename>.  &OfflineIMAP;
        ships with a file named <filename>offlineimap.conf</filename>
        that you should copy to that location and then edit.  This file is
        vital to proper operation of the system; it sets everything you need
        to run &OfflineIMAP;.  Full documentation for the configuration file
        is included within the sample file.
      </para>
      <para>
        &OfflineIMAP; also ships a file named
        <filename>offlineimap.conf.minimal</filename> that you can also try.
          It's useful if you want to get started with
          the most basic feature set, and you can read about other features
          later with <filename>offlineimap.conf</filename>.
      </para>
    </refsect1>

    <refsect1>
      <title>Options</title>
      <para>
        Most configuration is done via the configuration file.  Nevertheless,
        there are a few command-line options that you may set for
        &OfflineIMAP;.
      </para>

      <variablelist>
        <varlistentry><term>-1</term>
          <listitem><para>Disable most multithreading operations and use
            solely a single-connection
            sync.  This effectively sets the <property>maxsyncaccounts</property>
            and all <property>maxconnections</property> configuration file
            variables to 1.
          </para></listitem>
        </varlistentry>
        <varlistentry><term>-P <replaceable>profiledir</replaceable></term>
          <listitem><para>Sets &OfflineIMAP; into profile mode.  The program
            will create <replaceable>profiledir</replaceable>
            (it must not already exist).  As it runs, Python profiling 
            information
            about each thread is logged into profiledir.  Please note: This option
            is present for debugging and optimization only, and should NOT be used
            unless you have a specific reason to do so.  It will significantly
            slow program performance, may reduce reliability, and can generate
            huge amounts of data.  You must use the <option>-1</option> option when
            you use <option>-P</option>.
          </para></listitem>
        </varlistentry>
        <varlistentry><term>-a <replaceable>accountlist</replaceable></term>
          <listitem><para>Overrides the <property>accounts</property> option
            in the <property>general</property> section of the configuration
            file.  You might use this to exclude certain accounts, or to sync
            some accounts that you normally prefer not to.  Separate the
            accounts by commas, and use no embedded spaces.
          </para></listitem>
        </varlistentry>
        <varlistentry><term>-c <replaceable>configfile</replaceable></term>
          <listitem><para>Specifies a configuration file to use in lieu of
            the default, <filename>~/.offlineimaprc</filename>.
          </para></listitem>
        </varlistentry>
        <varlistentry><term>-d <replaceable>debugtype[,...]</replaceable></term>
          <listitem><para>Enables debugging for OfflineIMAP.  This is useful if
            you are trying to track down a malfunction or figure out what is going
            on under the hood.  I suggest that you use this with
            <option>-1</option> to make the results more sensible.</para>

            <para><option>-d</option> requires one or more debugtypes,
              separated by commas.  These define what exactly will be
              debugged, and include two options: <property>imap</property>
              and <property>maildir</property>.  The <property>imap</property>
              option will enable IMAP protocol stream and parsing debugging.  Note
              that the output may contain passwords, so take care to remove that
              from the debugging output before sending it to anyone else.  The
              <property>maildir</property> option will enable debugging for
              certain Maildir operations.
            </para></listitem>
          </varlistentry>
          <varlistentry><term>-o</term>
            <listitem><para>Run only once, ignoring all
              <property>autorefresh</property> settings in the configuration
              file.</para>
            </listitem>
          </varlistentry>
          <varlistentry><term>-h</term> <term>--help</term>
            <listitem><para>Show summary of options.</para></listitem>
          </varlistentry>
          <varlistentry><term>-u <replaceable>interface</replaceable></term>
            <listitem><para>Specifies an alternative user interface module
              to use.  This overrides the defailt specified in the
              configuration file.  The pre-defined options are listed in
              the User Interfaces section.</para>
            </listitem>
          </varlistentry>
      </variablelist>
    </refsect1>
    <refsect1>
      <title>User Interfaces</title>
      <para>&OfflineIMAP; has a pluggable user interface system that lets you choose how the
        program communicates information to you.  There are two graphical
        interfaces, two terminal interfaces, and two noninteractive interfaces
        suitable for scripting or logging purposes.  The
        <property>ui</property> option in the configuration file specifies
        user interface preferences.  The <option>-u</option> command-line
        option can override the configuration file setting.  The available
        values for the configuration file or command-line are described
        in this section.</para>
      <refsect2>
        <title>Tk.Blinkenlights</title>
        <para>Tk.Blinkenlights is an interface designed to be sleek, fun to watch, and
          informative of the overall picture of what &OfflineIMAP;
          is doing.  I consider it to be the best general-purpose interface in
          &OfflineIMAP;.
        </para>
        <para>
          Tk.Blinkenlights contains, by default, a small window with a row of
          LEDs, a small log, and a row of command buttons.
          The total size of the window is
          very small, so it uses little desktop space, yet it is quite
          functional.  The optional, toggleable, log shows more
          detail about what is happening and is color-coded to match the color
          of the lights.
        </para>
        <para>
          Tk.Blinkenlights is the only user interface that has configurable
          parameters; see the example <filename>offlineimap.conf</filename>
          for more details.
        </para>
        <para>
          Each light in the Blinkenlights interface represents a thread
          of execution -- that is, a particular task that &OfflineIMAP;
          is performing right now.  The colors indicate what task
          the particular thread is performing, and are as follows:
        </para>
        <variablelist>
          <varlistentry>
            <term>Black</term>
            <listitem><para>indicates that this light's thread has terminated; it will light up
              again later when new threads start up.  So, black indicates no
              activity.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Red (Meaning 1)</term>
            <listitem><para>is the color of the main program's thread, which basically does
              nothing but monitor the others.  It might remind you of HAL 9000 in
              <citation>2001</citation>.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Gray</term>
            <listitem><para>indicates that the thread is establishing a new connection to the IMAP
              server.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Purple</term>
            <listitem><para>is the color of an account synchronization thread that is monitoring
              the progress of the folders in that account (not generating any I/O).
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Cyan</term>
            <listitem><para>indicates that the thread is syncing a folder.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Green</term>
            <listitem><para>means that a folder's message list is being loaded.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Blue</term>
            <listitem><para>is the color of a message synchronization controller thread.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Orange</term>
            <listitem><para>indicates that an actual message is being copied.
              (We use fuschia for fake messages.)
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Red (meaning 2)</term>
            <listitem><para>indicates that a message is being deleted.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Yellow / bright orange</term>
            <listitem><para>indicates that message flags are being added.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Pink / bright red</term>
            <listitem><para>indicates that message flags are being removed.
            </para></listitem>
          </varlistentry>
          <varlistentry>
            <term>Red / Black Flashing</term>
            <listitem><para>corresponds to the countdown timer that runs between
              synchronizations.
            </para></listitem>
          </varlistentry>
        </variablelist>
        <para>The name of this interfaces derives from a bit of computer
          history.  Eric Raymond's <citation>Jargon File</citation> defines
          <firstterm>blinkenlights</firstterm>, in part, as:
        </para>
        <blockquote>
          <para>Front-panel diagnostic
            lights on a computer, esp. a dinosaur. Now that dinosaurs are rare,
            this term usually refers to status lights on a modem, network hub, or
            the like.
          </para>
          <para>
            This term derives from the last word of the famous blackletter-Gothic
            sign in mangled pseudo-German that once graced about half the computer
            rooms in the English-speaking world. One version ran in its entirety as
            follows:
          </para>
          <para>
            <emphasis>ACHTUNG!  ALLES LOOKENSPEEPERS!</emphasis>
          </para>
          <para>
            Das computermachine ist nicht fuer gefingerpoken und mittengrabben.
            Ist easy schnappen der springenwerk, blowenfusen und poppencorken
            mit spitzensparken.  Ist nicht fuer gewerken bei das dumpkopfen.
            Das rubbernecken sichtseeren keepen das cotten-pickenen hans in das
            pockets muss; relaxen und watchen das blinkenlichten.
          </para>
        </blockquote>
      </refsect2>

      <refsect2>
        <title>Curses.Blinkenlights</title>
        <para>
          Curses.Blinkenlights is an interface very similar to Tk.Blinkenlights,
          but is designed to be run in a console window (an xterm, Linux virtual
          terminal, etc.)  Since it doesn't have access to graphics, it isn't
          quite as pretty, but it still gets the job done.
        </para>
        <para>Please see the Tk.Blinkenlights section above for more
          information about the colors used in this interface.
        </para>
      </refsect2>

      <refsect2>
        <title>Tk.VerboseUI</title>
        <para>
          Tk.VerboseUI (formerly known as Tk.TkUI) is a graphical interface
          that presents a variable-sized window.  In the window, each
          currently-executing thread has a section where its name and current
          status are displayed.  This interface is best suited to people running
          on slower connections, as you get a lot of detail, but for fast
          connections, the detail may go by too quickly to be useful.  People
          with fast connections may wish to use Tk.Blinkenlights instead.
        </para>
      </refsect2>

      <refsect2>
        <title>TTY.TTYUI</title>
        <para>
          TTY.TTYUI interface is for people running in basic, non-color terminals.  It
          prints out basic status messages and is generally friendly to use on a console
          or xterm.
        </para>
      </refsect2>

      <refsect2>
        <title>Noninteractive.Basic</title>
        <para>
          Noninteractive.Basic is designed for situations in which &OfflineIMAP;
          will be run non-attended and the status of its execution will be
          logged.  You might use it, for instance, to have the system run
          automatically and
          e-mail you the results of the synchronization.  This user interface
          is not capable of reading a password from the keyboard; account
          passwords must be specified using one of the configuration file options.
        </para>
      </refsect2>

      <refsect2>
        <title>Noninteractive.Quiet</title>
        <para>
          Noninteractive.Quiet is designed for non-attended running in situations
          where normal status messages are not desired.  It will output nothing
          except errors and serious warnings.  Like Noninteractive.Basic,
          this user interface
          is not capable of reading a password from the keyboard; account
          passwords must be specified using one of the configuration file options.
        </para>
      </refsect2>

    </refsect1>

    <refsect1>
      <title>Examples</title>
      <para>Here are some example configurations for various situations.
        Please e-mail any other examples you have that may be useful to
        me.
      </para>

      <refsect2>
        <title>Multiple Accounts with Mutt</title>
        <para>
          This example shows you how to set up &OfflineIMAP; to
          synchronize multiple accounts with the mutt mail reader.
        </para>
        <para>
          Start by creating a directory to hold your folders by running
          <command>mkdir ~/Mail</command>.  Then, in your
          <filename>~/.offlineimaprc</filename>, specify:
        </para>
        <programlisting>accounts = Personal, Work</programlisting>
        <para>
          Make sure that you have both a <property>[Personal]</property>
          and a <property>[Work]</property> section, each with different
          <property>localfolder</property> path names.  Also, make sure
          to enable <property>[mbnames]</property>.
        </para>
        <para>
          In each account section, write something like this:
        </para>
        <programlisting>localfolders = ~/Mail/Personal</programlisting>
        <para>
          Finally, add these lines to your <filename>~/.muttrc</filename>:
        </para>
        <programlisting>source ~/path-to-mbnames-muttrc-mailboxes
folder-hook Personal set from="youremail@personal.com"
folder-hook Work set from="youremail@work.com"
set mbox_type=Maildir
set folder=$HOME/Mail
spoolfile=+Personal/INBOX</programlisting>
        <para>
          That's it!
        </para>
      </refsect2>

      <refsect2>
        <title>UW-IMAPD and References</title>
        <para>Some users with a UW-IMAPD server need to use &OfflineIMAP;'s
          "reference" feature to get at their mailboxes, specifying a reference
          of "~/Mail" or "#mh/" depending on the configuration.  The below
          configuration from docwhat@gerf.org
          shows using a <property>reference</property> of Mail, a <property>nametrans</property>
          that strips
          the leading Mail/ off incoming folder names, and a
          <property>folderfilter</property> that
          limits the folders synced to just three.
        </para>
        <programlisting>[Gerf]
localfolders = ~/Mail
remotehost = gerf.org
ssl = yes
remoteuser = docwhat
reference = Mail
# Trims off the preceeding Mail on all the folder names.
nametrans = lambda foldername: \
            re.sub('^Mail/', '', foldername)
# Yeah, you have to mention the Mail dir, even though it
# would seem intuitive that reference would trim it.
folderfilter = lambda foldername: foldername in [
      'Mail/INBOX',
      'Mail/list/zaurus-general',
      'Mail/list/zaurus-dev',
      ]
maxconnections = 1
holdconnectionopen = no</programlisting>
      </refsect2>

      <refsect2>
        <title>pythonfile Configuration File Option</title>
        <para>You can have &OfflineIMAP;
          load up a Python file before evaluating the
          configuration file options that are Python expressions.  This example
          is based on one supplied by Tommi Virtanen for this feature.
        </para>
        <para>
          In <filename>~/.offlineimap.rc</filename>, he adds these options:
        </para>
        <programlisting>[general]
pythonfile=~/.offlineimap.py
[foo]
foldersort=mycmp</programlisting>
        <para>
          Then, the <filename>~/.offlineimap.py</filename> file will
          contain:
        </para>
        <programlisting>prioritized = ['INBOX', 'personal', 'announce', 'list']

def mycmp(x, y):
   for prefix in prioritized:
       if x.startswith(prefix):
           return -1
       elif y.startswith(prefix):
           return +1
   return cmp(x, y)

def test_mycmp():
   import os, os.path
   folders=os.listdir(os.path.expanduser('~/data/mail/tv@hq.yok.utu.fi'))
   folders.sort(mycmp)
   print folders</programlisting>
        <para>
          This code snippet illustrates how the <property>foldersort</property>
          option can be customized with a Python function from the
          <property>pythonfile</property> to always synchronize certain
          folders first.
        </para>
      </refsect2>
    </refsect1>
      
    <refsect1>
      <title>Errors</title>
      <para>
        If you get one of some frequently-encountered or confusing errors,
        please check this section.
      </para>
      
      <refsect2>
        <title>UID validity problem for folder</title>
        <para>IMAP servers use a unique ID (UID) to refer to a specific message.
          This number is guaranteed to be unique to a particular message
          <emphasis>forever</emphasis>.
          No other message in the same folder will ever get the same
          UID.  UIDs are an integral part of &OfflineIMAP;'s synchronization
          scheme; they are used to match up messages on your computer to
          messages on the server.
        </para>

        <para>
          Sometimes, the UIDs on the server might get reset.  Usually this will
          happen if you delete and then recreate a folder.  When you create a
          folder, the server will often start the UID back from 1.  But
          &OfflineIMAP; might still have the UIDs from the previous folder by the
          same name stored.  &OfflineIMAP; will detect this condition and skip the
          folder.  This is GOOD, because it prevents data loss.
        </para>

        <para>
          You can fix it by removing your local folder and cache data.  For
          instance, if your folders are under <filename>~/Folders</filename>
          and the folder with the problem is INBOX, you'd type this:
        </para>

        <programlisting>rm -r ~/Folders/INBOX
rm -r ~/.offlineimap/AccountName/INBOX</programlisting>

        <para>
          (Of course, replace AccountName with the account name as specified
          in <filename>~/.offlineimaprc</filename>).
        </para>

        <para>Next time you run &OfflineIMAP;, it will re-download
          the folder with the
          new UIDs.  Note that the procedure specified above will lose any local
          changes made to the folder.
        </para>

        <para>
          Some IMAP servers are broken and do not support UIDs properly.  If you
          continue to get this error for all your folders even after performing
          the above procedure, it is likely that your IMAP server falls into
          this category.  &OfflineIMAP; is incompatible with such servers.
          Using &OfflineIMAP; with them will not destroy any mail, but at the same time,
          it will not actually synchronize it either.  (&OfflineIMAP; will detect
          this condition and abort prior to synchronization.)
        </para>
      </refsect2>
    </refsect1>
    <refsect1>
      <title>Other Frequently Asked Questions</title>
      <para>There are some other FAQs that might not fit into another section
        of the document, so they are discussed here.
      </para>

      <variablelist>
        <varlistentry><term>What platforms does &OfflineIMAP; run on?</term>
          <listitem><para>
            It should run on most platforms supported by Python, which are quite a
            few.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>I'm using Mutt.  Other IMAP sync programs require me to use "set maildir_trash=yes".  Do I need to do that with &OfflineIMAP;?</term>
          <listitem><para>
            No.  &OfflineIMAP; is smart enough to figure out message deletion without this extra
            crutch.  You'll get the best results if you don't use this setting, in
            fact.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>How do I specify the names of my folders?</term>
          <listitem><para>
            You do not need to.  &OfflineIMAP; is smart
            enough to automatically figure out what folders are present
            on the IMAP server and synchronize them.  You can use the
            <property>folderfilter</property> and <property>foldertrans</property>
            configuration file options to request certain folders and rename them
            as they come in if you like.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>How can I prevent certain folders from being synced?</term>
          <listitem><para>
            Use the <property>folderfilter</property> option in the configuration file.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>How can I add or delete a folder?</term>
          <listitem><para>
            &OfflineIMAP; does not currently provide this feature, but if you create a new
            folder on the IMAP server, it will be created locally automatically.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>Are there any other warnings that I should be aware of?</term>
          <listitem><para>
            Yes; see the Notes section below.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>What is the mailbox name recorder (mbnames) for?</term>
          <listitem><para>Some mail readers, such as Mutt, are not capable
            of automatically determining the names of your mailboxes.
            &OfflineIMAP; can help these programs by writing the names
            of the folders ni a format you specify.  See the example
            <filename>offlineimap.conf</filename> for details.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>Can I synchronize multiple accounts with &OfflineIMAP?</term>
          <listitem><para>Sure.  Just name them all in the
            <property>accounts</property> line in the <property>general</property>
            section of the configuration file, and add a per-account section
            for each one.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>Does &OfflineIMAP; support POP?</term>
          <listitem><para>No.  POP is not robust enough to do a completely reliable
            multi-machine synchronization like &OfflineIMAP; can do.  &OfflineIMAP;
            will not support it.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>Does &OfflineIMAP; support mailbox formats other than Maildir?</term>
          <listitem><para>Not at present.  There is no technical reason not to; just no
            demand yet.  Maildir is a superior format anyway.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>[technical] Why are your Maildir message filenames so huge?</term>
          <listitem><para>&OfflineIMAP; has two relevant principles: 1) never modifying your
            messages in any way and 2) ensuring 100% reliable synchronizations.
            In order to do a reliable sync, &OfflineIMAP;
            must have a way to
            uniquely identify each e-mail.  Three pieces of information are
            required to do this: your account name, the folder name, and the
            message UID.  The account name can be calculated from the path in
            which your messages are.  The folder name can usually be as well, BUT
            some mail clients move messages between folders by simply moving the
            file, leaving the name intact.
          </para>
          <para>
            So, &OfflineIMAP; must store both a UID folder ID.  The folder ID is
            necessary so &OfflineIMAP; can detect a message moved to a different
            folder.  &OfflineIMAP; stores the UID (U= number) and an md5sum of the
            foldername (FMD5= number) to facilitate this.
          </para></listitem>
        </varlistentry>

        <varlistentry><term>What is the speed of &OfflineIMAP;'s sync?</term>
          <listitem><para>OfflineIMAP
            versions 2.0 and above contain a multithreaded system.  A good way to
            experiment is by setting <property>maxsyncaccounts</property> to 3 and <property>maxconnections</property> to 3
            in each account clause.
          </para>
          <para>This lets OfflineIMAP open up multiple connections simultaneously.
            That will let it process multiple folders and messages at once.  In
            most cases, this will increase performance of the sync.
          </para>
          <para>Don't set the number too high.  If you do that, things might actually
            slow down as your link gets saturated.  Also, too many connections can
            cause mail servers to have excessive load.  Administrators might take
            unkindly to this, and the server might bog down.  There are many
            variables in the optimal setting; experimentation may help.
          </para>
          <para>An informal benchmark yields these results for my setup:
          </para>
          <itemizedlist>
            <listitem><para>10 minutes with MacOS X Mail.app "manual cache"
              </para></listitem>
            <listitem><para>5 minutes with GNUS agent sync</para></listitem>
            <listitem><para>20 seconds with OfflineIMAP 1.x</para></listitem>
            <listitem><para>9 seconds with OfflineIMAP 2.x</para></listitem>
            <listitem><para>3 seconds with OfflineIMAP 3.x "cold start"</para></listitem>
            <listitem><para>2 seconds with OfflineIMAP 3.x "held connection"</para></listitem>
          </itemizedlist>
        </listitem></varlistentry>
      </variablelist>
    </refsect1>

    <refsect1>
      <title>Conforming To</title>
      <itemizedlist>
        <listitem><para>Internet Message Access Protocol version 4rev1 (IMAP 4rev1) as
          specified in RFC2060</para></listitem>
        <listitem><para>CRAM-MD5 as specified in RFC2195</para></listitem>
        <listitem><para>Maildir as specified in
          <ulink url="http://www.qmail.org/qmail-manual-html/man5/maildir.html">the Maildir manpage</ulink> and
          <ulink url="http://cr.yp.to/proto/maildir.html">the qmail website</ulink>.</para></listitem>
        <listitem><para>Standard Python 2.2.1 as implemented on POSIX-compliant systems.</para></listitem>
      </itemizedlist>
    </refsect1>

    <refsect1>
      <title>Notes</title>
      <refsect2>
        <title>Deleting Local Folders</title>
        <para>&OfflineIMAP; does a two-way synchronization.  That is, if you
          make a change to the mail on the server, it will be propogated to your
          local copy, and vise-versa.  Some people might think that it would be
          wise to just delete all their local mail folders periodically.  If you
          do this with &OfflineIMAP;, remember to also remove your local status
          cache (<filename>~/.offlineimap</filename> by default).  Otherwise, &OfflineIMAP; will take
          this as an intentional deletion of many messages and will interpret
          your action as requesting them to be deleted from the server as well.
          (If you don't understand this, don't worry; you probably won't
          encounter this situation)
        </para>
      </refsect2>

      <refsect2>
        <title>Copying Messages Between Folders</title>
        <para>
          Normally, when you copy a message between folders or add a new message
          to a folder locally, &OfflineIMAP;
          will just do the right thing.  However, sometimes this can be tricky
          -- if your IMAP server does not provide the SEARCH command, or does
          not return something useful, &OfflineIMAP;
          cannot determine the new UID of the message.  So, in these rare
          instances, OfflineIMAP will upload the message to the IMAP server and
          delete it from your local folder.  Then, on your next sync, the
          message will be re-downloaded with the proper UID.
          &OfflineIMAP; makes sure that the message was properly uploaded before deleting it,
          so there should be no risk of data loss.
        </para>
      </refsect2>

      <refsect2>
        <title>Use with Evolution</title>
        <para>&OfflineIMAP; can work with Evolution.  To do so, first configure
          your &OfflineIMAP; account to have
          <option>sep = /</option> in its configuration.  Then, configure
          Evolution with the
          "Maildir-format mail directories" server type.  For the path, you will need to
          specify the name of the top-level folder
          <emphasis>inside</emphasis> your &OfflineIMAP; storage location.
          You're now set!
        </para>
      </refsect2>

      <refsect2>
        <title>Use with KMail</title>
        <para>At this time, I believe that &OfflineIMAP; is not compatible
          with KMail.  KMail cannot work in any mode other than to move
          all messages out of all folders immediately, which (besides being annoying
          and fundamentally broken) is incompatible with &OfflineIMAP;.
        </para>
      </refsect2>

      <refsect2>
        <title>Mailing List</title>
        <para>There is an OfflineIMAP mailing list available.
          To subscribe, send the text "Subscribe" in the subject of a mail to
          offlineimap-request@complete.org.  To post, send the message to
          offlineimap@complete.org.
        </para>
      </refsect2>

      <refsect2>
        <title>Bugs</title>
        <para>Reports of bugs should be sent via e-mail to the
          &OfflineIMAP; bug-tracking system (BTS) at
          offlineimap@bugs.complete.org or submitted online using
          the <ulink url="http://bugs.complete.org/">web interface</ulink>.
        </para>
        <para>
          The Web site also lists all current bugs, where you can check their
          status or contribute to fixing them.
        </para>
      </refsect2>
    </refsect1>

    <refsect1>
      <title>Copyright</title>
      <para>OfflineIMAP, and this manual, are Copyright &copy; 2002, 2003 John Goerzen.</para>

      <para>
        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.
      </para>

      <para>
        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
      </para>

      <para>
        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA</para>

      <para>imaplib.py comes from the Python dev tree and is licensed under
        the GPL-compatible PSF license as stated in the file
        <filename>COPYRIGHT</filename> in the &OfflineIMAP;
         distribution.
      </para>
    </refsect1>

    <refsect1>
      <title>Author</title>
      <para>&OfflineIMAP;, its libraries, documentation, and all included files, except where
        noted, was written by John Goerzen (<address>jgoerzen@complete.org</address>) and
        copyright is held as stated in the COPYRIGHT section.
      </para>

      <para>
        &OfflineIMAP; may be downloaded, and information found, from is
        hopepage via either <ulink url="gopher://quux.org/1/devel/offlineimap">Gopher</ulink>
        or <ulink url="http://quux.org/devel/offlineimap">HTTP</ulink>.
      </para>

      <para>
        &OfflineIMAP; may also be downloaded using Subversion.  Additionally,
        the distributed tar.gz may be updated with a simple "svn update"
        command; it is ready to go.  For information on getting OfflineIMAP
        with Subversion, please visit the
        <ulink url="http://svn.complete.org/">complete.org Subversion page</ulink>.
      </para>

    </refsect1>

    <refsect1>
      <title>See Also</title>
      <para><application>mutt</application>(1),
        <application>python</application>(1)
      </para>
    </refsect1>
  </refentry>
</reference>