http://sourceforge.net/projects/eximdsn/

DSN Support for Exim. This patch allows Exim 4.xx to support the sending of email Delivery Status Notifications.

http://sourceforge.net/projects/eximdsn/files/eximdsn/eximdsn-patch-1.3/
http://sourceforge.net/projects/eximdsn/files/eximdsn/eximdsn-patch-1.3/exim_476_dsn_1_3.patch/download
http://sourceforge.net/projects/eximdsn/files/eximdsn/eximdsn-patch-1.3/README_Exim_DSN_476.txt/download

http://downloads.sourceforge.net/project/eximdsn/eximdsn/eximdsn-patch-1.3/exim_476_dsn_1_3.patch
http://downloads.sourceforge.net/project/eximdsn/eximdsn/eximdsn-patch-1.3/README_Exim_DSN_476.txt