Rails 3.1 action mailer useage
<tr id=<%= dom_id(blast)%> class="blast">
  <td><%= blast.id %></td>
  <td><%= blast.description %></td>
  <td><%= blast.subject %></td>
  <td><%= blast.last_sent %></td>
  <td><%= blast.created_at.strftime('%D at %I:%M %p') %></td>
  <td><%= link_to "Destroy", blast,:remote => true,  :confirm => "Are You Sure?", :method => :delete %></td>
  <td><%= link_to "Edit",edit_blast_path(blast), :remote => true, :action => "edit"%></td>
  <td><%= link_to "Mail",blast, :action => 'show', :remote => true%></td>

class BlastsController < ApplicationController
  before_filter :require_user
  respond_to :html, :js
  def index
    @blasts = Blast.page(params[:page]).per(10)

  end

  def show
    @customer = Customer.all
    @blast = Blast.find(params[:id])
  end

  def create
    @blast = Blast.new(params[:blast])

    if @blast.save
    respond_with @blast, :location => blasts_url

    end
  end

  def destroy
    @blast = Blast.find(params[:id])
    @blast.destroy

    respond_with @blast, :location => blasts_url
  end

  def edit
    @blast = Blast.find(params[:id])
    respond_with @blast, :location => blasts_url
  end

  def update
    @blast = Blast.find(params[:id])
    @blast.update_attributes(params[:blast])

    respond_with @blast, :location => blasts_url
  end
end

class BlastMailer < ActionMailer::Base
  default from: "info@ratatouillecatering.com"

  def mail_blast(customer, blast)
    @customer = customer
    @blast=blast
    @customer.each do |f|
    mail(:to => f.email, :subject => "hello")
    end
  end
end