1 files changed, 72 insertions, 22 deletions
diff --git a/Documentation/process/email-clients.rst b/Documentation/process/email-clients.rst
index c9e4ce2613c0..471e1f93fa09 100644
--- a/Documentation/process/email-clients.rst
+++ b/Documentation/process/email-clients.rst
@@ -25,6 +25,11 @@ attachments, but then the attachments should have content-type
 it makes quoting portions of the patch more difficult in the patch
 review process.
 
+It's also strongly recommended that you use plain text in your email body,
+for patches and other emails alike. https://useplaintext.email may be useful
+for information on how to configure your preferred email client, as well as
+listing recommended email clients should you not already have a preference.
+
 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.
@@ -272,36 +277,61 @@ Thunderbird (GUI)
 Thunderbird is an Outlook clone that likes to mangle text, but there are ways
 to coerce it into behaving.
 
+After doing the modifications, this includes installing the extensions,
+you need to restart Thunderbird.
+
 - 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.
+
+  The easiest thing to do with Thunderbird and patches is to use extensions
+  which open your favorite external editor.
+
+  Here are some example extensions which are capable of doing this.
+
+  - "External Editor Revived"
+
+    https://github.com/Frederick888/external-editor-revived
+
+    https://addons.thunderbird.net/en-GB/thunderbird/addon/external-editor-revived/
+
+    It requires installing a "native messaging host".
+    Please read the wiki which can be found here:
+    https://github.com/Frederick888/external-editor-revived/wiki
+
+  - "External Editor"
+
+    https://github.com/exteditor/exteditor
+
+    To do this, download and install the extension, then open the
+    :menuselection:`compose` window, add a button for it using
+    :menuselection:`View-->Toolbars-->Customize...`
+    then just click on the new button when you wish to use the external editor.
+
+    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 --nofork"`` (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.
+- Edit your Thunderbird config settings so that it won't use ``format=flowed``!
+  Go to your main window and find the button for your main dropdown menu.
+  :menuselection:`Main Menu-->Preferences-->General-->Config Editor...`
+  to bring up the thunderbird's registry editor.
 
-- Set ``mailnews.send_plaintext_flowed`` to ``false``
+  - Set ``mailnews.send_plaintext_flowed`` to ``false``
 
-- Set ``mailnews.wraplength`` from ``72`` to ``0``
+  - Set ``mailnews.wraplength`` from ``72`` to ``0``
 
-- :menuselection:`View-->Message Body As-->Plain Text`
+- Don't write HTML messages! Go to the main window
+  :menuselection:`Main Menu-->Account Settings-->youracc@server.something-->Composition & Addressing`!
+  There you can disable the option "Compose messages in HTML format".
 
-- :menuselection:`View-->Character Encoding-->Unicode (UTF-8)`
+- Open messages only as plain text! Go to the main window
+  :menuselection:`Main Menu-->View-->Message Body As-->Plain Text`!
 
 TkRat (GUI)
 ***********
@@ -320,3 +350,23 @@ 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.
+
+Proton Mail
+***********
+
+Proton Mail has a "feature" where it looks up keys using Web Key Directory
+(WKD) and encrypts mail to any recipients for which it finds a key.
+Kernel.org publishes the WKD for all developers who have kernel.org accounts.
+As a result, emails sent using Proton Mail to kernel.org addresses will be
+encrypted.
+Unfortunately, Proton Mail does not provide a mechanism to disable the
+automatic encryption, viewing it as a privacy feature.
+The automatic encryption feature is also enabled for mail sent via the Proton
+Mail Bridge, so this affects all outgoing messages, including patches sent with
+``git send-email``.
+Encrypted mail adds unnecessary friction, as other developers may not have mail
+clients, or tooling, configured for use with encrypted mail and some mail
+clients may encrypt responses to encrypted mail for all recipients, including
+the mailing lists.
+Unless a way to disable this "feature" is introduced, Proton Mail is unsuited
+to kernel development.