Add some information about mailing list managers.

draft/mailing_list_managers.md

@@ -0,0 +1,71 @@
+# Mailing list integration of Delta Chat
+
+A collection of information to help with the integration of mailing lists into Delta Chat.
+
+## Chat name
+
+How should the chat be titled?
+
+It could be taken from the email header `List-Id`:
+
+### Mailman 
+
+* Schema: `${list-description} <${list-local-part}.${list-domain}>`
+* $list-description could be many words, should be truncated. Could also be empty, though.
+
+### Schleuder
+* Schema: `<${list-local-part}.${list-domain}>`
+* No name available.
+* Could be absent: <https://0xacab.org/schleuder/schleuder/-/blob/master/lib/schleuder/mail/message.rb#L357-358>.
+
+
+### Sympa
+* Schema: `<${list-local-part}.${list-domain}>`
+* No name available.
+* Always present <https://github.com/sympa-community/sympa/blob/sympa-6.2/src/lib/Sympa/Spindle/TransformOutgoing.pm#L110-L118>, <https://github.com/sympa-community/sympa/blob/sympa-6.2/src/lib/Sympa/List.pm#L6832-L6833>.
+
+
+## Sender name
+
+What's the name of the person that actually sent the message?
+
+Some MLM change the sender information to avoid problems with DMARC.
+
+### Mailman
+
+* Since v2.1.16 the `From` depends on the list's configuration and possibly on the sender-domain's DMARC-configuration — i.e. messages from the same list can arrive one of the Variants A-D!
+* Documentation of config options:
+ * <https://wiki.list.org/DOC/Mailman%202.1%20List%20Administrators%20Manual#line-544>,
+ * <https://wiki.list.org/DOC/Mailman%202.1%20List%20Administrators%20Manual#line-163>,
+ * <https://wiki.list.org/DEV/DMARC>
+* Variant A: `From` is unchanged.
+* Variant B. `From` is mangled like this: `${sender-name} via ${list-name} <${list-addr-spec}>`. The original sender is put into `Reply-To`.
+* Variant C. `From` is mangled like this: `${sender-name} <${encoded-sender-addr-spec}@${list-domain}>`. The original sender is put into `Reply-To`.
+* Variant D: `From` is set to ${list-name-addr}, the originally sent message is included as mime-part.
+* Variant E: `From` is set to ${list-name-addr}, original sender information is removed.
+
+### Schleuder
+
+* Visible only in mime-body (which is possibly encrypted), or not at all.
+* The first `text/plain` mime-part may include the information, as taken from the original message: `From: ${sender-name-addr}`.
+
+### Sympa
+* Depends on the list's configuration.
+* Documentation:
+ * <https://sympa-community.github.io/manual/customize/dmarc-protection.html>,
+ * <https://sympa-community.github.io/gpldoc/man/sympa.conf.5.html#dmarc-protection>.
+* Variant A: `From` is unchanged.
+* Variant B: `From` is mangled like Mailman Variant B, but the original sender information is put into `X-Original-From`.
+
+
+## Autocrypt
+
+### Mailman
+* Not supported.
+
+### Schleuder
+* A list's key is included in sent messages (as of version 3.5.0) (optional, by default active): <https://0xacab.org/schleuder/schleuder/-/blob/master/lib/schleuder/mail/message.rb#L349-355>.
+* Incoming keys are not yet looked at (that feature is planned: <https://0xacab.org/schleuder/schleuder/issues/435>).
+
+### Sympa
+* Not supported.