Is anyone using this hook? I've already implemented performance improvement as described in item 1. of my request: http://trac.roundcube.net/ticket/1485690
I use BODY[] instead of BODY.PEEK[] in FETCH command to set the \Seen flag implicitly. This gives one STORE command less. Now the hook... it is executed in show.inc when message hasn't got the \Seen flag set. With my changes the hook will be never executed. I propose to remove this hook.