An example of a terrible approach to a contact form.

awful_contact_us_controller.rb

class ContactUsController < ApplicationController
  def index
  end

  def send_enquiry
    if contact_form_valid?
      ContactUsMailer.send_enquiry(contact_form_params).deliver
      return redirect_to action: :thank_you
    end
    render :index
  end

  def thank_you
  end

  private
  def contact_form_valid?
    contact_form_params[:name].present? && contact_form_params[:email].present? && contact_form_params[:email].present?
  end

  def contact_form_params
    params.require(:contact_form).permit!
  end
end