если вы хотите переписать отправителя конверта в маршрутизаторе, используйте действие «ошибки _в» в этом маршрутизаторе
errors_to = list-bounces@example.org
http://www.exim.org/exim-html-current/doc/html/spec_html/ch-generic_options_for_routers.htmlговорит частично:
If an address for which errors_to has been set ends up being delivered over SMTP, the envelope sender for that delivery is the errors_to value, so that any bounces that are generated by other MTAs on the delivery route are also sent there.