+ ^p - previous message
+ b - toggle folding of message bodies
+ c - toggle folding of citations
+ h - toggle folding of extra header lines
+ i - toggle folding of signatures
+ m - compose a new message
+ r - reply to the message
+ s - enter search criteria
+ q - return to search display
+ ? - reveal the message and thread IDs of what's under cursor
+ ^] - search using word under cursor
+
+ [notmuch-compose]
+ When you're writing an email, you're in this mode.
+
+ Insert-mode keybindings:
+ <Tab> - go to the next header line
+
+ Normal-mode keybindings:
+ <Tab> - go to the next header line
+ ,s - send this message
+ ,q - abort this message