class RuboCop::Cop::Rails::MailerName

def on_send(node)
  return unless class_new_definition?(node)
  casgn_parent = node.each_ancestor(:casgn).first
  return unless casgn_parent
  name = casgn_parent.children[1]
  return if mailer_suffix?(name)
  add_offense(casgn_parent.loc.name) do |corrector|
    autocorrect(corrector, casgn_parent)
  end
end