我在注册时设置 ActionMailer 时遇到困难:
config/initializers/setup_mail.rb
ActionMailer::Base.smtp_settings = {
 :address              => "smtp.gmail.com",
 :port                 => "587",
 :domain               => "mail.gmail.com",
 :user_name            => "my_gmail_user_name",
 :password             => "my_gmail_pw",
 :authentication       => "plain",
 :enable_starttls_auto => true
}
ActionMailer::Base.default_url_options[:host] = "localhost:3000"
Mail.register_interceptor( DevelopmentMailInterceptor ) if Rails.env.development?
users_controller.rb
def create
  @user = User.new( params[:user] )
  respond_to do |format|
    if @user.save
      UserMailer.welcome_email( @user ).deliver
      format.html{ redirect_to( @user, :notice => 'Account successfully created.' ) }
      format.json{ render :xml => @user, :status => :created, :location => @user }
    else
      format.html { render :action => "new" }
      format.xml  { render :xml => @user.errors, :status => :unprocessable_entity }
    end
end
app/mailers/user_mailer.rb
class UserMailer < ActionMailer::Base
  default :from "no-reply@myapp.com"
  def welcome_email( user )
    @user = user
    @url = "http://localhost:3000/login"
    mail( :to => user.email, :subject => 'Welcome to app' )
  end
end
lib/development_mail_interceptor.rb
class DevelopmentMailInterceptor
  def self.delivering_email(message)
    message.subject = "#{message.to} #{message.subject}"
    message.to = "mydump@email.com"
  end
end
我没有收到任何电子邮件发送到我的转储电子邮件中DevelopmentMailInterceptor。