open latter
1 Add Gem 2 gem "letter_opener", :group => :development 3 bundle install 4 config/environments/development.rb config.action_mailer.delivery_method = :letter_opener config.action_mailer.perform_deliveries = true 5 rails g mailer UserMailer mailers/user_mailer.rb class UserMailer < ApplicationMailer def example(user) @user = user mail(to: @user.email, subject: 'Test Email for Letter Opener') end end 6 app/views/user_mailer/example.html.erb <h1>Welcome <%= @user.email %>! </h1> 7 users_controller.rb def index UserMailer.example(User.new(email: 'bo@samurails.com')).deliver @users = User.all end