lib/generators/rspec/mailer/templates/preview.rb
<% module_namespacing do -%> # Preview all emails at http://localhost:3000/rails/mailers/<%= file_path %> class <%= class_name %>Preview < ActionMailer::Preview <% actions.each do |action| -%> # Preview this email at http://localhost:3000/rails/mailers/<%= file_path %>/<%= action %> def <%= action %> <%= class_name %>.<%= action %> end <% end -%> end <% end -%>