xref: /linux/Documentation/process/email-clients.rst (revision e2be04c7f9958dde770eeb8b30e829ca969b37bb)
1.. _email_clients:
2
3Email clients info for Linux
4============================
5
6Git
7---
8
9These days most developers use ``git send-email`` instead of regular
10email clients.  The man page for this is quite good.  On the receiving
11end, maintainers use ``git am`` to apply the patches.
12
13If you are new to ``git`` then send your first patch to yourself.  Save it
14as raw text including all the headers.  Run ``git am raw_email.txt`` and
15then review the changelog with ``git log``.  When that works then send
16the patch to the appropriate mailing list(s).
17
18General Preferences
19-------------------
20
21Patches for the Linux kernel are submitted via email, preferably as
22inline text in the body of the email.  Some maintainers accept
23attachments, but then the attachments should have content-type
24``text/plain``.  However, attachments are generally frowned upon because
25it makes quoting portions of the patch more difficult in the patch
26review process.
27
28Email clients that are used for Linux kernel patches should send the
29patch text untouched.  For example, they should not modify or delete tabs
30or spaces, even at the beginning or end of lines.
31
32Don't send patches with ``format=flowed``.  This can cause unexpected
33and unwanted line breaks.
34
35Don't let your email client do automatic word wrapping for you.
36This can also corrupt your patch.
37
38Email clients should not modify the character set encoding of the text.
39Emailed patches should be in ASCII or UTF-8 encoding only.
40If you configure your email client to send emails with UTF-8 encoding,
41you avoid some possible charset problems.
42
43Email clients should generate and maintain References: or In-Reply-To:
44headers so that mail threading is not broken.
45
46Copy-and-paste (or cut-and-paste) usually does not work for patches
47because tabs are converted to spaces.  Using xclipboard, xclip, and/or
48xcutsel may work, but it's best to test this for yourself or just avoid
49copy-and-paste.
50
51Don't use PGP/GPG signatures in mail that contains patches.
52This breaks many scripts that read and apply the patches.
53(This should be fixable.)
54
55It's a good idea to send a patch to yourself, save the received message,
56and successfully apply it with 'patch' before sending patches to Linux
57mailing lists.
58
59
60Some email client (MUA) hints
61-----------------------------
62
63Here are some specific MUA configuration hints for editing and sending
64patches for the Linux kernel.  These are not meant to be complete
65software package configuration summaries.
66
67
68Legend:
69
70- TUI = text-based user interface
71- GUI = graphical user interface
72
73Alpine (TUI)
74************
75
76Config options:
77
78In the :menuselection:`Sending Preferences` section:
79
80- :menuselection:`Do Not Send Flowed Text` must be ``enabled``
81- :menuselection:`Strip Whitespace Before Sending` must be ``disabled``
82
83When composing the message, the cursor should be placed where the patch
84should appear, and then pressing :kbd:`CTRL-R` let you specify the patch file
85to insert into the message.
86
87Claws Mail (GUI)
88****************
89
90Works. Some people use this successfully for patches.
91
92To insert a patch use :menuselection:`Message-->Insert` File (:kbd:`CTRL-I`)
93or an external editor.
94
95If the inserted patch has to be edited in the Claws composition window
96"Auto wrapping" in
97:menuselection:`Configuration-->Preferences-->Compose-->Wrapping` should be
98disabled.
99
100Evolution (GUI)
101***************
102
103Some people use this successfully for patches.
104
105When composing mail select: Preformat
106  from :menuselection:`Format-->Paragraph Style-->Preformatted` (:kbd:`CTRL-7`)
107  or the toolbar
108
109Then use:
110:menuselection:`Insert-->Text File...` (:kbd:`ALT-N x`)
111to insert the patch.
112
113You can also ``diff -Nru old.c new.c | xclip``, select
114:menuselection:`Preformat`, then paste with the middle button.
115
116Kmail (GUI)
117***********
118
119Some people use Kmail successfully for patches.
120
121The default setting of not composing in HTML is appropriate; do not
122enable it.
123
124When composing an email, under options, uncheck "word wrap". The only
125disadvantage is any text you type in the email will not be word-wrapped
126so you will have to manually word wrap text before the patch. The easiest
127way around this is to compose your email with word wrap enabled, then save
128it as a draft. Once you pull it up again from your drafts it is now hard
129word-wrapped and you can uncheck "word wrap" without losing the existing
130wrapping.
131
132At the bottom of your email, put the commonly-used patch delimiter before
133inserting your patch:  three hyphens (``---``).
134
135Then from the :menuselection:`Message` menu item, select insert file and
136choose your patch.
137As an added bonus you can customise the message creation toolbar menu
138and put the :menuselection:`insert file` icon there.
139
140Make the composer window wide enough so that no lines wrap. As of
141KMail 1.13.5 (KDE 4.5.4), KMail will apply word wrapping when sending
142the email if the lines wrap in the composer window. Having word wrapping
143disabled in the Options menu isn't enough. Thus, if your patch has very
144long lines, you must make the composer window very wide before sending
145the email. See: https://bugs.kde.org/show_bug.cgi?id=174034
146
147You can safely GPG sign attachments, but inlined text is preferred for
148patches so do not GPG sign them.  Signing patches that have been inserted
149as inlined text will make them tricky to extract from their 7-bit encoding.
150
151If you absolutely must send patches as attachments instead of inlining
152them as text, right click on the attachment and select properties, and
153highlight :menuselection:`Suggest automatic display` to make the attachment
154inlined to make it more viewable.
155
156When saving patches that are sent as inlined text, select the email that
157contains the patch from the message list pane, right click and select
158:menuselection:`save as`.  You can use the whole email unmodified as a patch
159if it was properly composed.  There is no option currently to save the email
160when you are actually viewing it in its own window -- there has been a request
161filed at kmail's bugzilla and hopefully this will be addressed.  Emails are
162saved as read-write for user only so you will have to chmod them to make them
163group and world readable if you copy them elsewhere.
164
165Lotus Notes (GUI)
166*****************
167
168Run away from it.
169
170IBM Verse (Web GUI)
171*******************
172
173See Lotus Notes.
174
175Mutt (TUI)
176**********
177
178Plenty of Linux developers use ``mutt``, so it must work pretty well.
179
180Mutt doesn't come with an editor, so whatever editor you use should be
181used in a way that there are no automatic linebreaks.  Most editors have
182an :menuselection:`insert file` option that inserts the contents of a file
183unaltered.
184
185To use ``vim`` with mutt::
186
187  set editor="vi"
188
189If using xclip, type the command::
190
191  :set paste
192
193before middle button or shift-insert or use::
194
195  :r filename
196
197if you want to include the patch inline.
198(a)ttach works fine without ``set paste``.
199
200You can also generate patches with ``git format-patch`` and then use Mutt
201to send them::
202
203    $ mutt -H 0001-some-bug-fix.patch
204
205Config options:
206
207It should work with default settings.
208However, it's a good idea to set the ``send_charset`` to::
209
210  set send_charset="us-ascii:utf-8"
211
212Mutt is highly customizable. Here is a minimum configuration to start
213using Mutt to send patches through Gmail::
214
215  # .muttrc
216  # ================  IMAP ====================
217  set imap_user = 'yourusername@gmail.com'
218  set imap_pass = 'yourpassword'
219  set spoolfile = imaps://imap.gmail.com/INBOX
220  set folder = imaps://imap.gmail.com/
221  set record="imaps://imap.gmail.com/[Gmail]/Sent Mail"
222  set postponed="imaps://imap.gmail.com/[Gmail]/Drafts"
223  set mbox="imaps://imap.gmail.com/[Gmail]/All Mail"
224
225  # ================  SMTP  ====================
226  set smtp_url = "smtp://username@smtp.gmail.com:587/"
227  set smtp_pass = $imap_pass
228  set ssl_force_tls = yes # Require encrypted connection
229
230  # ================  Composition  ====================
231  set editor = `echo \$EDITOR`
232  set edit_headers = yes  # See the headers when editing
233  set charset = UTF-8     # value of $LANG; also fallback for send_charset
234  # Sender, email address, and sign-off line must match
235  unset use_domain        # because joe@localhost is just embarrassing
236  set realname = "YOUR NAME"
237  set from = "username@gmail.com"
238  set use_from = yes
239
240The Mutt docs have lots more information:
241
242    http://dev.mutt.org/trac/wiki/UseCases/Gmail
243
244    http://dev.mutt.org/doc/manual.html
245
246Pine (TUI)
247**********
248
249Pine has had some whitespace truncation issues in the past, but these
250should all be fixed now.
251
252Use alpine (pine's successor) if you can.
253
254Config options:
255
256- ``quell-flowed-text`` is needed for recent versions
257- the ``no-strip-whitespace-before-send`` option is needed
258
259
260Sylpheed (GUI)
261**************
262
263- Works well for inlining text (or using attachments).
264- Allows use of an external editor.
265- Is slow on large folders.
266- Won't do TLS SMTP auth over a non-SSL connection.
267- Has a helpful ruler bar in the compose window.
268- Adding addresses to address book doesn't understand the display name
269  properly.
270
271Thunderbird (GUI)
272*****************
273
274Thunderbird is an Outlook clone that likes to mangle text, but there are ways
275to coerce it into behaving.
276
277- Allow use of an external editor:
278  The easiest thing to do with Thunderbird and patches is to use an
279  "external editor" extension and then just use your favorite ``$EDITOR``
280  for reading/merging patches into the body text.  To do this, download
281  and install the extension, then add a button for it using
282  :menuselection:`View-->Toolbars-->Customize...` and finally just click on it
283  when in the :menuselection:`Compose` dialog.
284
285  Please note that "external editor" requires that your editor must not
286  fork, or in other words, the editor must not return before closing.
287  You may have to pass additional flags or change the settings of your
288  editor. Most notably if you are using gvim then you must pass the -f
289  option to gvim by putting ``/usr/bin/gvim -f`` (if the binary is in
290  ``/usr/bin``) to the text editor field in :menuselection:`external editor`
291  settings. If you are using some other editor then please read its manual
292  to find out how to do this.
293
294To beat some sense out of the internal editor, do this:
295
296- Edit your Thunderbird config settings so that it won't use ``format=flowed``.
297  Go to :menuselection:`edit-->preferences-->advanced-->config editor` to bring up
298  the thunderbird's registry editor.
299
300- Set ``mailnews.send_plaintext_flowed`` to ``false``
301
302- Set ``mailnews.wraplength`` from ``72`` to ``0``
303
304- :menuselection:`View-->Message Body As-->Plain Text`
305
306- :menuselection:`View-->Character Encoding-->Unicode (UTF-8)`
307
308TkRat (GUI)
309***********
310
311Works.  Use "Insert file..." or external editor.
312
313Gmail (Web GUI)
314***************
315
316Does not work for sending patches.
317
318Gmail web client converts tabs to spaces automatically.
319
320At the same time it wraps lines every 78 chars with CRLF style line breaks
321although tab2space problem can be solved with external editor.
322
323Another problem is that Gmail will base64-encode any message that has a
324non-ASCII character. That includes things like European names.
325