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+.. _email_clients:
+
+Email clients info for Linux
+============================
+
+Git
+---
+
+These days most developers use ``git send-email`` instead of regular
+email clients.  The man page for this is quite good.  On the receiving
+end, maintainers use ``git am`` to apply the patches.
+
+If you are new to ``git`` then send your first patch to yourself.  Save it
+as raw text including all the headers.  Run ``git am raw_email.txt`` and
+then review the changelog with ``git log``.  When that works then send
+the patch to the appropriate mailing list(s).
+
+General Preferences
+-------------------
+
+Patches for the Linux kernel are submitted via email, preferably as
+inline text in the body of the email.  Some maintainers accept
+attachments, but then the attachments should have content-type
+``text/plain``.  However, attachments are generally frowned upon because
+it makes quoting portions of the patch more difficult in the patch
+review process.
+
+Email clients that are used for Linux kernel patches should send the
+patch text untouched.  For example, they should not modify or delete tabs
+or spaces, even at the beginning or end of lines.
+
+Don't send patches with ``format=flowed``.  This can cause unexpected
+and unwanted line breaks.
+
+Don't let your email client do automatic word wrapping for you.
+This can also corrupt your patch.
+
+Email clients should not modify the character set encoding of the text.
+Emailed patches should be in ASCII or UTF-8 encoding only.
+If you configure your email client to send emails with UTF-8 encoding,
+you avoid some possible charset problems.
+
+Email clients should generate and maintain References: or In-Reply-To:
+headers so that mail threading is not broken.
+
+Copy-and-paste (or cut-and-paste) usually does not work for patches
+because tabs are converted to spaces.  Using xclipboard, xclip, and/or
+xcutsel may work, but it's best to test this for yourself or just avoid
+copy-and-paste.
+
+Don't use PGP/GPG signatures in mail that contains patches.
+This breaks many scripts that read and apply the patches.
+(This should be fixable.)
+
+It's a good idea to send a patch to yourself, save the received message,
+and successfully apply it with 'patch' before sending patches to Linux
+mailing lists.
+
+
+Some email client (MUA) hints
+-----------------------------
+
+Here are some specific MUA configuration hints for editing and sending
+patches for the Linux kernel.  These are not meant to be complete
+software package configuration summaries.
+
+
+Legend:
+
+- TUI = text-based user interface
+- GUI = graphical user interface
+
+Alpine (TUI)
+************
+
+Config options:
+
+In the :menuselection:`Sending Preferences` section:
+
+- :menuselection:`Do Not Send Flowed Text` must be ``enabled``
+- :menuselection:`Strip Whitespace Before Sending` must be ``disabled``
+
+When composing the message, the cursor should be placed where the patch
+should appear, and then pressing :kbd:`CTRL-R` let you specify the patch file
+to insert into the message.
+
+Claws Mail (GUI)
+****************
+
+Works. Some people use this successfully for patches.
+
+To insert a patch use :menuselection:`Message-->Insert` File (:kbd:`CTRL-I`)
+or an external editor.
+
+If the inserted patch has to be edited in the Claws composition window
+"Auto wrapping" in
+:menuselection:`Configuration-->Preferences-->Compose-->Wrapping` should be
+disabled.
+
+Evolution (GUI)
+***************
+
+Some people use this successfully for patches.
+
+When composing mail select: Preformat
+  from :menuselection:`Format-->Paragraph Style-->Preformatted` (:kbd:`CTRL-7`)
+  or the toolbar
+
+Then use:
+:menuselection:`Insert-->Text File...` (:kbd:`ALT-N x`)
+to insert the patch.
+
+You can also ``diff -Nru old.c new.c | xclip``, select
+:menuselection:`Preformat`, then paste with the middle button.
+
+Kmail (GUI)
+***********
+
+Some people use Kmail successfully for patches.
+
+The default setting of not composing in HTML is appropriate; do not
+enable it.
+
+When composing an email, under options, uncheck "word wrap". The only
+disadvantage is any text you type in the email will not be word-wrapped
+so you will have to manually word wrap text before the patch. The easiest
+way around this is to compose your email with word wrap enabled, then save
+it as a draft. Once you pull it up again from your drafts it is now hard
+word-wrapped and you can uncheck "word wrap" without losing the existing
+wrapping.
+
+At the bottom of your email, put the commonly-used patch delimiter before
+inserting your patch:  three hyphens (``---``).
+
+Then from the :menuselection:`Message` menu item, select insert file and
+choose your patch.
+As an added bonus you can customise the message creation toolbar menu
+and put the :menuselection:`insert file` icon there.
+
+Make the composer window wide enough so that no lines wrap. As of
+KMail 1.13.5 (KDE 4.5.4), KMail will apply word wrapping when sending
+the email if the lines wrap in the composer window. Having word wrapping
+disabled in the Options menu isn't enough. Thus, if your patch has very
+long lines, you must make the composer window very wide before sending
+the email. See: https://bugs.kde.org/show_bug.cgi?id=174034
+
+You can safely GPG sign attachments, but inlined text is preferred for
+patches so do not GPG sign them.  Signing patches that have been inserted
+as inlined text will make them tricky to extract from their 7-bit encoding.
+
+If you absolutely must send patches as attachments instead of inlining
+them as text, right click on the attachment and select properties, and
+highlight :menuselection:`Suggest automatic display` to make the attachment
+inlined to make it more viewable.
+
+When saving patches that are sent as inlined text, select the email that
+contains the patch from the message list pane, right click and select
+:menuselection:`save as`.  You can use the whole email unmodified as a patch
+if it was properly composed.  There is no option currently to save the email
+when you are actually viewing it in its own window -- there has been a request
+filed at kmail's bugzilla and hopefully this will be addressed.  Emails are
+saved as read-write for user only so you will have to chmod them to make them
+group and world readable if you copy them elsewhere.
+
+Lotus Notes (GUI)
+*****************
+
+Run away from it.
+
+IBM Verse (Web GUI)
+*******************
+
+See Lotus Notes.
+
+Mutt (TUI)
+**********
+
+Plenty of Linux developers use ``mutt``, so it must work pretty well.
+
+Mutt doesn't come with an editor, so whatever editor you use should be
+used in a way that there are no automatic linebreaks.  Most editors have
+an :menuselection:`insert file` option that inserts the contents of a file
+unaltered.
+
+To use ``vim`` with mutt::
+
+  set editor="vi"
+
+If using xclip, type the command::
+
+  :set paste
+
+before middle button or shift-insert or use::
+
+  :r filename
+
+if you want to include the patch inline.
+(a)ttach works fine without ``set paste``.
+
+You can also generate patches with ``git format-patch`` and then use Mutt
+to send them::
+
+    $ mutt -H 0001-some-bug-fix.patch
+
+Config options:
+
+It should work with default settings.
+However, it's a good idea to set the ``send_charset`` to::
+
+  set send_charset="us-ascii:utf-8"
+
+Mutt is highly customizable. Here is a minimum configuration to start
+using Mutt to send patches through Gmail::
+
+  # .muttrc
+  # ================  IMAP ====================
+  set imap_user = 'yourusername@gmail.com'
+  set imap_pass = 'yourpassword'
+  set spoolfile = imaps://imap.gmail.com/INBOX
+  set folder = imaps://imap.gmail.com/
+  set record="imaps://imap.gmail.com/[Gmail]/Sent Mail"
+  set postponed="imaps://imap.gmail.com/[Gmail]/Drafts"
+  set mbox="imaps://imap.gmail.com/[Gmail]/All Mail"
+
+  # ================  SMTP  ====================
+  set smtp_url = "smtp://username@smtp.gmail.com:587/"
+  set smtp_pass = $imap_pass
+  set ssl_force_tls = yes # Require encrypted connection
+
+  # ================  Composition  ====================
+  set editor = `echo \$EDITOR`
+  set edit_headers = yes  # See the headers when editing
+  set charset = UTF-8     # value of $LANG; also fallback for send_charset
+  # Sender, email address, and sign-off line must match
+  unset use_domain        # because joe@localhost is just embarrassing
+  set realname = "YOUR NAME"
+  set from = "username@gmail.com"
+  set use_from = yes
+
+The Mutt docs have lots more information:
+
+    http://dev.mutt.org/trac/wiki/UseCases/Gmail
+
+    http://dev.mutt.org/doc/manual.html
+
+Pine (TUI)
+**********
+
+Pine has had some whitespace truncation issues in the past, but these
+should all be fixed now.
+
+Use alpine (pine's successor) if you can.
+
+Config options:
+
+- ``quell-flowed-text`` is needed for recent versions
+- the ``no-strip-whitespace-before-send`` option is needed
+
+
+Sylpheed (GUI)
+**************
+
+- Works well for inlining text (or using attachments).
+- Allows use of an external editor.
+- Is slow on large folders.
+- Won't do TLS SMTP auth over a non-SSL connection.
+- Has a helpful ruler bar in the compose window.
+- Adding addresses to address book doesn't understand the display name
+  properly.
+
+Thunderbird (GUI)
+*****************
+
+Thunderbird is an Outlook clone that likes to mangle text, but there are ways
+to coerce it into behaving.
+
+- Allow use of an external editor:
+  The easiest thing to do with Thunderbird and patches is to use an
+  "external editor" extension and then just use your favorite ``$EDITOR``
+  for reading/merging patches into the body text.  To do this, download
+  and install the extension, then add a button for it using
+  :menuselection:`View-->Toolbars-->Customize...` and finally just click on it
+  when in the :menuselection:`Compose` dialog.
+
+  Please note that "external editor" requires that your editor must not
+  fork, or in other words, the editor must not return before closing.
+  You may have to pass additional flags or change the settings of your
+  editor. Most notably if you are using gvim then you must pass the -f
+  option to gvim by putting ``/usr/bin/gvim -f`` (if the binary is in
+  ``/usr/bin``) to the text editor field in :menuselection:`external editor`
+  settings. If you are using some other editor then please read its manual
+  to find out how to do this.
+
+To beat some sense out of the internal editor, do this:
+
+- Edit your Thunderbird config settings so that it won't use ``format=flowed``.
+  Go to :menuselection:`edit-->preferences-->advanced-->config editor` to bring up
+  the thunderbird's registry editor.
+
+- Set ``mailnews.send_plaintext_flowed`` to ``false``
+
+- Set ``mailnews.wraplength`` from ``72`` to ``0``
+
+- :menuselection:`View-->Message Body As-->Plain Text`
+
+- :menuselection:`View-->Character Encoding-->Unicode (UTF-8)`
+
+TkRat (GUI)
+***********
+
+Works.  Use "Insert file..." or external editor.
+
+Gmail (Web GUI)
+***************
+
+Does not work for sending patches.
+
+Gmail web client converts tabs to spaces automatically.
+
+At the same time it wraps lines every 78 chars with CRLF style line breaks
+although tab2space problem can be solved with external editor.
+
+Another problem is that Gmail will base64-encode any message that has a
+non-ASCII character. That includes things like European names.