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 28It's also strongly recommended that you use plain text in your email body, 29for patches and other emails alike. https://useplaintext.email may be useful 30for information on how to configure your preferred email client, as well as 31listing recommended email clients should you not already have a preference. 32 33Email clients that are used for Linux kernel patches should send the 34patch text untouched. For example, they should not modify or delete tabs 35or spaces, even at the beginning or end of lines. 36 37Don't send patches with ``format=flowed``. This can cause unexpected 38and unwanted line breaks. 39 40Don't let your email client do automatic word wrapping for you. 41This can also corrupt your patch. 42 43Email clients should not modify the character set encoding of the text. 44Emailed patches should be in ASCII or UTF-8 encoding only. 45If you configure your email client to send emails with UTF-8 encoding, 46you avoid some possible charset problems. 47 48Email clients should generate and maintain "References:" or "In-Reply-To:" 49headers so that mail threading is not broken. 50 51Copy-and-paste (or cut-and-paste) usually does not work for patches 52because tabs are converted to spaces. Using xclipboard, xclip, and/or 53xcutsel may work, but it's best to test this for yourself or just avoid 54copy-and-paste. 55 56Don't use PGP/GPG signatures in mail that contains patches. 57This breaks many scripts that read and apply the patches. 58(This should be fixable.) 59 60It's a good idea to send a patch to yourself, save the received message, 61and successfully apply it with 'patch' before sending patches to Linux 62mailing lists. 63 64 65Some email client (MUA) hints 66----------------------------- 67 68Here are some specific MUA configuration hints for editing and sending 69patches for the Linux kernel. These are not meant to be complete 70software package configuration summaries. 71 72 73Legend: 74 75- TUI = text-based user interface 76- GUI = graphical user interface 77 78Alpine (TUI) 79************ 80 81Config options: 82 83In the :menuselection:`Sending Preferences` section: 84 85- :menuselection:`Do Not Send Flowed Text` must be ``enabled`` 86- :menuselection:`Strip Whitespace Before Sending` must be ``disabled`` 87 88When composing the message, the cursor should be placed where the patch 89should appear, and then pressing :kbd:`CTRL-R` let you specify the patch file 90to insert into the message. 91 92Claws Mail (GUI) 93**************** 94 95Works. Some people use this successfully for patches. 96 97To insert a patch use :menuselection:`Message-->Insert File` (:kbd:`CTRL-I`) 98or an external editor. 99 100If the inserted patch has to be edited in the Claws composition window 101"Auto wrapping" in 102:menuselection:`Configuration-->Preferences-->Compose-->Wrapping` should be 103disabled. 104 105Evolution (GUI) 106*************** 107 108Some people use this successfully for patches. 109 110When composing mail select: Preformat 111 from :menuselection:`Format-->Paragraph Style-->Preformatted` (:kbd:`CTRL-7`) 112 or the toolbar 113 114Then use: 115:menuselection:`Insert-->Text File...` (:kbd:`ALT-N x`) 116to insert the patch. 117 118You can also ``diff -Nru old.c new.c | xclip``, select 119:menuselection:`Preformat`, then paste with the middle button. 120 121Kmail (GUI) 122*********** 123 124Some people use Kmail successfully for patches. 125 126The default setting of not composing in HTML is appropriate; do not 127enable it. 128 129When composing an email, under options, uncheck "word wrap". The only 130disadvantage is any text you type in the email will not be word-wrapped 131so you will have to manually word wrap text before the patch. The easiest 132way around this is to compose your email with word wrap enabled, then save 133it as a draft. Once you pull it up again from your drafts it is now hard 134word-wrapped and you can uncheck "word wrap" without losing the existing 135wrapping. 136 137At the bottom of your email, put the commonly-used patch delimiter before 138inserting your patch: three hyphens (``---``). 139 140Then from the :menuselection:`Message` menu item, select 141:menuselection:`insert file` and choose your patch. 142As an added bonus you can customise the message creation toolbar menu 143and put the :menuselection:`insert file` icon there. 144 145Make the composer window wide enough so that no lines wrap. As of 146KMail 1.13.5 (KDE 4.5.4), KMail will apply word wrapping when sending 147the email if the lines wrap in the composer window. Having word wrapping 148disabled in the Options menu isn't enough. Thus, if your patch has very 149long lines, you must make the composer window very wide before sending 150the email. See: https://bugs.kde.org/show_bug.cgi?id=174034 151 152You can safely GPG sign attachments, but inlined text is preferred for 153patches so do not GPG sign them. Signing patches that have been inserted 154as inlined text will make them tricky to extract from their 7-bit encoding. 155 156If you absolutely must send patches as attachments instead of inlining 157them as text, right click on the attachment and select :menuselection:`properties`, 158and highlight :menuselection:`Suggest automatic display` to make the attachment 159inlined to make it more viewable. 160 161When saving patches that are sent as inlined text, select the email that 162contains the patch from the message list pane, right click and select 163:menuselection:`save as`. You can use the whole email unmodified as a patch 164if it was properly composed. Emails are saved as read-write for user only so 165you will have to chmod them to make them group and world readable if you copy 166them elsewhere. 167 168Lotus Notes (GUI) 169***************** 170 171Run away from it. 172 173IBM Verse (Web GUI) 174******************* 175 176See Lotus Notes. 177 178Mutt (TUI) 179********** 180 181Plenty of Linux developers use ``mutt``, so it must work pretty well. 182 183Mutt doesn't come with an editor, so whatever editor you use should be 184used in a way that there are no automatic linebreaks. Most editors have 185an :menuselection:`insert file` option that inserts the contents of a file 186unaltered. 187 188To use ``vim`` with mutt:: 189 190 set editor="vi" 191 192If using xclip, type the command:: 193 194 :set paste 195 196before middle button or shift-insert or use:: 197 198 :r filename 199 200if you want to include the patch inline. 201(a)ttach works fine without ``set paste``. 202 203You can also generate patches with ``git format-patch`` and then use Mutt 204to send them:: 205 206 $ mutt -H 0001-some-bug-fix.patch 207 208Config options: 209 210It should work with default settings. 211However, it's a good idea to set the ``send_charset`` to:: 212 213 set send_charset="us-ascii:utf-8" 214 215Mutt is highly customizable. Here is a minimum configuration to start 216using Mutt to send patches through Gmail:: 217 218 # .muttrc 219 # ================ IMAP ==================== 220 set imap_user = 'yourusername@gmail.com' 221 set imap_pass = 'yourpassword' 222 set spoolfile = imaps://imap.gmail.com/INBOX 223 set folder = imaps://imap.gmail.com/ 224 set record="imaps://imap.gmail.com/[Gmail]/Sent Mail" 225 set postponed="imaps://imap.gmail.com/[Gmail]/Drafts" 226 set mbox="imaps://imap.gmail.com/[Gmail]/All Mail" 227 228 # ================ SMTP ==================== 229 set smtp_url = "smtp://username@smtp.gmail.com:587/" 230 set smtp_pass = $imap_pass 231 set ssl_force_tls = yes # Require encrypted connection 232 233 # ================ Composition ==================== 234 set editor = `echo \$EDITOR` 235 set edit_headers = yes # See the headers when editing 236 set charset = UTF-8 # value of $LANG; also fallback for send_charset 237 # Sender, email address, and sign-off line must match 238 unset use_domain # because joe@localhost is just embarrassing 239 set realname = "YOUR NAME" 240 set from = "username@gmail.com" 241 set use_from = yes 242 243The Mutt docs have lots more information: 244 245 https://gitlab.com/muttmua/mutt/-/wikis/UseCases/Gmail 246 247 http://www.mutt.org/doc/manual/ 248 249Pine (TUI) 250********** 251 252Pine has had some whitespace truncation issues in the past, but these 253should all be fixed now. 254 255Use alpine (pine's successor) if you can. 256 257Config options: 258 259- ``quell-flowed-text`` is needed for recent versions 260- the ``no-strip-whitespace-before-send`` option is needed 261 262 263Sylpheed (GUI) 264************** 265 266- Works well for inlining text (or using attachments). 267- Allows use of an external editor. 268- Is slow on large folders. 269- Won't do TLS SMTP auth over a non-SSL connection. 270- Has a helpful ruler bar in the compose window. 271- Adding addresses to address book doesn't understand the display name 272 properly. 273 274Thunderbird (GUI) 275***************** 276 277Thunderbird is an Outlook clone that likes to mangle text, but there are ways 278to coerce it into behaving. 279 280After doing the modifications, this includes installing the extensions, 281you need to restart Thunderbird. 282 283- Allow use of an external editor: 284 285 The easiest thing to do with Thunderbird and patches is to use extensions 286 which open your favorite external editor. 287 288 Here are some example extensions which are capable of doing this. 289 290 - "External Editor Revived" 291 292 https://github.com/Frederick888/external-editor-revived 293 294 https://addons.thunderbird.net/en-GB/thunderbird/addon/external-editor-revived/ 295 296 It requires installing a "native messaging host". 297 Please read the wiki which can be found here: 298 https://github.com/Frederick888/external-editor-revived/wiki 299 300 - "External Editor" 301 302 https://github.com/exteditor/exteditor 303 304 To do this, download and install the extension, then open the 305 :menuselection:`compose` window, add a button for it using 306 :menuselection:`View-->Toolbars-->Customize...` 307 then just click on the new button when you wish to use the external editor. 308 309 Please note that "External Editor" requires that your editor must not 310 fork, or in other words, the editor must not return before closing. 311 You may have to pass additional flags or change the settings of your 312 editor. Most notably if you are using gvim then you must pass the -f 313 option to gvim by putting ``/usr/bin/gvim --nofork"`` (if the binary is in 314 ``/usr/bin``) to the text editor field in :menuselection:`external editor` 315 settings. If you are using some other editor then please read its manual 316 to find out how to do this. 317 318To beat some sense out of the internal editor, do this: 319 320- Edit your Thunderbird config settings so that it won't use ``format=flowed``! 321 Go to your main window and find the button for your main dropdown menu. 322 :menuselection:`Main Menu-->Preferences-->General-->Config Editor...` 323 to bring up the thunderbird's registry editor. 324 325 - Set ``mailnews.send_plaintext_flowed`` to ``false`` 326 327 - Set ``mailnews.wraplength`` from ``72`` to ``0`` 328 329- Don't write HTML messages! Go to the main window 330 :menuselection:`Main Menu-->Account Settings-->youracc@server.something-->Composition & Addressing`! 331 There you can disable the option "Compose messages in HTML format". 332 333- Open messages only as plain text! Go to the main window 334 :menuselection:`Main Menu-->View-->Message Body As-->Plain Text`! 335 336TkRat (GUI) 337*********** 338 339Works. Use "Insert file..." or external editor. 340 341Gmail (Web GUI) 342*************** 343 344Does not work for sending patches. 345 346Gmail web client converts tabs to spaces automatically. 347 348At the same time it wraps lines every 78 chars with CRLF style line breaks 349although tab2space problem can be solved with external editor. 350 351Another problem is that Gmail will base64-encode any message that has a 352non-ASCII character. That includes things like European names. 353 354Proton Mail 355*********** 356 357Proton Mail has a "feature" where it looks up keys using Web Key Directory 358(WKD) and encrypts mail to any recipients for which it finds a key. 359Kernel.org publishes the WKD for all developers who have kernel.org accounts. 360As a result, emails sent using Proton Mail to kernel.org addresses will be 361encrypted. 362Unfortunately, Proton Mail does not provide a mechanism to disable the 363automatic encryption, viewing it as a privacy feature. 364The automatic encryption feature is also enabled for mail sent via the Proton 365Mail Bridge, so this affects all outgoing messages, including patches sent with 366``git send-email``. 367Encrypted mail adds unnecessary friction, as other developers may not have mail 368clients, or tooling, configured for use with encrypted mail and some mail 369clients may encrypt responses to encrypted mail for all recipients, including 370the mailing lists. 371Unless a way to disable this "feature" is introduced, Proton Mail is unsuited 372to kernel development. 373