Added SMTP pre-send hook [#178] Customize headers to show at the top of a read message [#338] Changed Improve attachments command [#281] Fixed In-Reply-To not set properly when replying to a message [#323] Cc missing or invalid when replying to a message [#324] Notmuch backend hangs [#329] Maildir e2e tests [#335] JSON API for listings [#331]