Amazon Web Services - AWS EC2 - Ubuntu 14.04
Postfix Configuration
CONFIGURE Postfix
# vim /etc/postfix/main.cf
smtpd_milters = inet:127.0.0.1:8891
non_smtpd_milters = $smtpd_milters
milter_default_action = accept
# service opendkim restart
# service postfix restart