Export of distribution lists had been completely disabled some time ago. It has been reactivated again for our internal CSV format and may be switched off with a new parameter export_dlists. If false distribution lists will not be exported. If the parameter is not set, it defaults to true.

http://ox.io/appsuite/api/export?action=CSV&folder=x&session=y&content_dispo sition=attachment&export_dlists=false