Add the following lines in your config/enviroments/production.rb

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = YAML.load File.open("#{RAILS_ROOT}/config/mailer.yml")

And then create the yaml file config/mailer.yml :

---
  :enable_starttls_auto: true # This is how you tell ActionMailler to use tls
  :address: smtp.gmail.com
  :port: 587
  :domain: gmail.com
  :user_name: my_username #You should type your username, you should not include the "@gmail.com".
  :password: my_password #You should type your password
  :authentication: :plain

That’s it!

Now take a look in this notifier class example:

class Notifier < ActionMailer::Base
  def activation_instructions(user)
    @recipients  = "#{user.email}"
    #@from        = "Miguel <my_username@gmail.com>" # Doesn't work anymore 
    @from        = "my_username@gmail.com"
    @subject     = "[Card-Sorting] "
    @sent_on     = Time.now
    @subject    += "Important"
    @body[:user] = user
  end
end

There is a lack of backward compatible. Due to some changes in the latest versions you cannot use that syntax anymore, if you are upgrading from old versions be careful, you should only simply specify your email to get it correctly parsed.

http://blog.media72.net/2008/05/13/javascript-auto-include-rails-plugin/

I haven’t tried it yet but seems a good way to maintain your .js files organized.