Most third-party HOWTOs that reference Debian and claim to make things
   easy suggest dumping a pre-fabricated, static config file to
   /etc/exim4/exim4.conf. This is considered bad advice by the Debian
   maintainers since you're going to disable all updates and service
   magic that Debian might deliver in the future this way. If you do not
   know exactly what you're doing here, this is a bad choice. We try to
   comment on external HOWTOs found on the web in the [5]Debian Exim4
   User FAQ to help you find out which advice to follow.

     5. http://wiki.debian.org/PkgExim4UserFAQ