Add a draft how an AEAP MVP could look

draft/aeap-mvp.rst

@@ -0,0 +1,33 @@
+AEAP MVP
+========
+
+Changes to the UIs
+------------------
+
+- The secondary self addresses (see below) are shown in the UI, but not editable.
+
+That's all!
+
+Changes in the core
+-------------------
+
+- We have one primary self address and any number of secondary self addresses. `is_self_addr()` checks all of them.
+
+- If the user does a reconfigure and changes the email address, the previous address is added as a secondary self address.
+
+  - don't forget to deduplicate secondary self addresses in case the user switches back and forth between addresses).
+
+  - The key stays the same.
+
+- No changes for 1:1 chats, there simply is a new one
+
+- When we send a message to a group, and the primary address is not a member of a group, but a secondary address is:
+  
+  Add Chat-Group-Member-Removed=<old address> and Chat-Group-Member-Added=<new address> headers to this message
+
+  - On the receiving side, make sure that we accept this (even in verified groups) if the message is signed and the key stayed the same
+
+Other
+-----
+
+- The user is responsible that messages to the old address arrive at the new address, for example by configuring the old provider to forward all emails to the new one.