++ Make message store code modular
+
+ Notmuch is built on the assumption that the message store is a
+ collection of message files in directories (roughly Maildir
+ format). This performs suboptimally for a wide range of systems,
+ especially with large numbers of messages. Modularising the
+ message store code to move this assumption into the implementation
+ rather than the interface would allow adding support for different
+ message stores like the traditional [mbox
+ formats](http://homepage.ntlworld.com./jonathan.deboynepollard/FGA/mail-mbox-formats.html)
+ as well as more experimental approaches like using git as an object
+ storage (similar to how [[nmbug]] operates).
+