The config file:
sudo vim /usr/share/redmine/config
Related links:
http://www.redmine.org/projects/redmine/wiki/HowTo_Install_Redmine_25x_on_Ubuntu_1404_with_Apache2_Phusion_Passenger_MySQL_and_Subversion //good
http://blog.csdn.net/pochuanpiao/article/details/12840985 //good
http://www.redmine.org/projects/redmine/wiki/EmailConfiguration //email configuration
http://www.aiezu.com/code/exchange2010_smtp_unrecognized_authentication_type.html //504 5.7.4 Unrecognized authentication type
http://xianghuaclm.blog.163.com/blog/static/66687832012046921370/
ubuntu + redmine + email--setup
原文：http://www.cnblogs.com/zhongyuan/p/4236117.html