Hello!
Yesterday I filed a feature request for Mail-Followup-To support: http://trac.roundcube.net/ticket/1485547
I'd like to try to implement it (or parts of it) myself, but at first I'm curious about your position to Mail-Followup-To support. Do you want this feature?
I'm asking because coding a patch that will not find its way into the tree can be frustrating, so positive feedback on this will clearly boost my motivation ;)
LG, Daniel
List info: http://lists.roundcube.net/dev/