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
136:menuselection:`insert file` and choose 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 :menuselection:`properties`,
153and highlight :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.  Emails are saved as read-write for user only so
160you will have to chmod them to make them group and world readable if you copy
161them elsewhere.
162
163Lotus Notes (GUI)
164*****************
165
166Run away from it.
167
168IBM Verse (Web GUI)
169*******************
170
171See Lotus Notes.
172
173Mutt (TUI)
174**********
175
176Plenty of Linux developers use ``mutt``, so it must work pretty well.
177
178Mutt doesn't come with an editor, so whatever editor you use should be
179used in a way that there are no automatic linebreaks.  Most editors have
180an :menuselection:`insert file` option that inserts the contents of a file
181unaltered.
182
183To use ``vim`` with mutt::
184
185  set editor="vi"
186
187If using xclip, type the command::
188
189  :set paste
190
191before middle button or shift-insert or use::
192
193  :r filename
194
195if you want to include the patch inline.
196(a)ttach works fine without ``set paste``.
197
198You can also generate patches with ``git format-patch`` and then use Mutt
199to send them::
200
201    $ mutt -H 0001-some-bug-fix.patch
202
203Config options:
204
205It should work with default settings.
206However, it's a good idea to set the ``send_charset`` to::
207
208  set send_charset="us-ascii:utf-8"
209
210Mutt is highly customizable. Here is a minimum configuration to start
211using Mutt to send patches through Gmail::
212
213  # .muttrc
214  # ================  IMAP ====================
215  set imap_user = 'yourusername@gmail.com'
216  set imap_pass = 'yourpassword'
217  set spoolfile = imaps://imap.gmail.com/INBOX
218  set folder = imaps://imap.gmail.com/
219  set record="imaps://imap.gmail.com/[Gmail]/Sent Mail"
220  set postponed="imaps://imap.gmail.com/[Gmail]/Drafts"
221  set mbox="imaps://imap.gmail.com/[Gmail]/All Mail"
222
223  # ================  SMTP  ====================
224  set smtp_url = "smtp://username@smtp.gmail.com:587/"
225  set smtp_pass = $imap_pass
226  set ssl_force_tls = yes # Require encrypted connection
227
228  # ================  Composition  ====================
229  set editor = `echo \$EDITOR`
230  set edit_headers = yes  # See the headers when editing
231  set charset = UTF-8     # value of $LANG; also fallback for send_charset
232  # Sender, email address, and sign-off line must match
233  unset use_domain        # because joe@localhost is just embarrassing
234  set realname = "YOUR NAME"
235  set from = "username@gmail.com"
236  set use_from = yes
237
238The Mutt docs have lots more information:
239
240    https://gitlab.com/muttmua/mutt/-/wikis/UseCases/Gmail
241
242    http://www.mutt.org/doc/manual/
243
244Pine (TUI)
245**********
246
247Pine has had some whitespace truncation issues in the past, but these
248should all be fixed now.
249
250Use alpine (pine's successor) if you can.
251
252Config options:
253
254- ``quell-flowed-text`` is needed for recent versions
255- the ``no-strip-whitespace-before-send`` option is needed
256
257
258Sylpheed (GUI)
259**************
260
261- Works well for inlining text (or using attachments).
262- Allows use of an external editor.
263- Is slow on large folders.
264- Won't do TLS SMTP auth over a non-SSL connection.
265- Has a helpful ruler bar in the compose window.
266- Adding addresses to address book doesn't understand the display name
267  properly.
268
269Thunderbird (GUI)
270*****************
271
272Thunderbird is an Outlook clone that likes to mangle text, but there are ways
273to coerce it into behaving.
274
275- Allow use of an external editor:
276  The easiest thing to do with Thunderbird and patches is to use an
277  "external editor" extension and then just use your favorite ``$EDITOR``
278  for reading/merging patches into the body text.  To do this, download
279  and install the extension, then add a button for it using
280  :menuselection:`View-->Toolbars-->Customize...` and finally just click on it
281  when in the :menuselection:`Compose` dialog.
282
283  Please note that "external editor" requires that your editor must not
284  fork, or in other words, the editor must not return before closing.
285  You may have to pass additional flags or change the settings of your
286  editor. Most notably if you are using gvim then you must pass the -f
287  option to gvim by putting ``/usr/bin/gvim -f`` (if the binary is in
288  ``/usr/bin``) to the text editor field in :menuselection:`external editor`
289  settings. If you are using some other editor then please read its manual
290  to find out how to do this.
291
292To beat some sense out of the internal editor, do this:
293
294- Edit your Thunderbird config settings so that it won't use ``format=flowed``.
295  Go to :menuselection:`edit-->preferences-->advanced-->config editor` to bring up
296  the thunderbird's registry editor.
297
298- Set ``mailnews.send_plaintext_flowed`` to ``false``
299
300- Set ``mailnews.wraplength`` from ``72`` to ``0``
301
302- :menuselection:`View-->Message Body As-->Plain Text`
303
304- :menuselection:`View-->Character Encoding-->Unicode (UTF-8)`
305
306TkRat (GUI)
307***********
308
309Works.  Use "Insert file..." or external editor.
310
311Gmail (Web GUI)
312***************
313
314Does not work for sending patches.
315
316Gmail web client converts tabs to spaces automatically.
317
318At the same time it wraps lines every 78 chars with CRLF style line breaks
319although tab2space problem can be solved with external editor.
320
321Another problem is that Gmail will base64-encode any message that has a
322non-ASCII character. That includes things like European names.
323