config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
:address              => "smtp.gmail.com",:port                 => 587,:domain               => "mydomain.com",:user_name            => "username",:password             => "password",:authentication       => 'plain',:enable_starttls_auto => true  }

config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = true

但是每当gitlab尝试发送电子邮件时：

Sent mail to user@my.domain.com (10ms)
Completed 500 Internal Server Error in 29ms

535-5.7.1 Username and Password not accepted

服务器运行ruby 1.9.3p194.为什么谷歌应用程序不接受用户名/密码？