redmine中邮件服务的配置(腾讯企业信箱)

安装的是bitnami的redmine stack，运行在一个阿里云的ubuntu服务器实例上：
Environment:
  Redmine version                2.4.1.stable
  Ruby version                   1.9.3-p484 (2013-11-22) [x86_64-linux]
  Rails version                  3.2.16
  Environment                    production
  Database adapter               Mysql2

邮箱是腾讯的企业免费信箱。
配置文件位于：/redmine的安装目录/apps/redmine/htdocs/config/configuration.yml
配置内容：

production:
  email_delivery:
    delivery_method: :smtp
    smtp_settings:
      tls: true
      enable_starttls_auto: true
      address: "smtp.exmail.qq.com"
      port: 465
      domain: "abcdef.cn"
      authentication: :login
      user_name: "redmine@abcdef.cn"
      password: "abcdefgh"