Exemples de configurations
http://www.linuxquestions.org/questions/debian-26/where-to-add-relay-domains-exim4-548475/?s=4889255e65246356499469e9b7ce37c9
http://lists.alioth.debian.org/pipermail/pkg-exim4-users/2005-October/000321.html
http://www.gossamer-threads.com/lists/exim/users/73793