class Exceptions < Merb::Controller
 
  ...
 
  cattr_accessor :email_addresses
 
  def internal_server_error
    @exception = self.params[:exception]
    @exception_name = @exception.name.split("_").map {|x| x.capitalize}.join(" ")
    notify_emails if Merb.env?(:production)
    render
  end
 
private
 
  def notify_emails
    begin      
      return if self.class.email_addresses.blank?
 
      subject = "[#{@exception.class::STATUS}] #{@exception_name}: #{@exception.message}"
      mail_body = render(:template => "exceptions/error_email.txt")
 
      email = Merb::Mailer.new({ 
        :to => self.class.email_addresses.join(", "), 
        :from => "MyApp", 
        :subject => subject, 
        :text => mail_body })
 
      email.deliver!
 
    rescue Error => e
      Merb.logger.error("Error sending error email: #{e}")
    end
  end
 
 
end

<%= @exception_name %> (<%= @exception.class::STATUS %>): <%= @exception.message %>
 
URL: <%= "#{request.protocol}#{request.env["HTTP_HOST"]}#{request.uri}" %>
Parameters: <%= params[:original_params].inspect %>
 
<% @exception.backtrace.each_with_index do |line, index| %>
  <%= (line.match(/^([^:]+)/)[1] rescue 'unknown').sub(/\/((opt|usr)\/local\/lib\/(ruby\/)?(gems\/)?(1.8\/)?(gems\/)?|.+\/app\/)/, '') %>:<%=line%>
<% end %>

dependency "merb-mailer"
 
Merb::BootLoader.after_app_loads do
 
  ...
 
  # Mailer configuration
  Merb::Mailer.config = {:sendmail_path => "/usr/sbin/sendmail"}
  Merb::Mailer.delivery_method = :sendmail
  Exceptions.email_addresses = ["my@email.com"]
end