Rails 3 Action Mailer Gmail

I am trying to understand how to properly configure Action Mailer for Rails 3 to work with Gmail. Read the article by Ryan Bates and also read the edge Rails page article. Ryan's article said to put the config details in /config/initializers/setup_mail.rb initializer file

ActionMailer::Base.smtp_settings = {  
  :address              => "smtp.gmail.com",  
  开发者_如何学运维:port                 => 587,  
  :domain               => "asciicasts.com",  
  :user_name            => "asciicasts",  
  :password             => "secret",  
  :authentication       => "plain",  
  :enable_starttls_auto => true  
} 

But the edge Rails article said put it in the config/environments/$RAILS_ENV.rb, anyone know which is the preferred way of doing it?

---

Put it wherever it makes sense for your particular project. If you need different settings for different environments then do that, otherwise you can put it into an initializer.