ruby on rails - Preventing sending e-mail to user if he didn't filled the e-mail field -

i have rails application, have visitors_controller homepage , contacts_controller contact form. website has single-paged, i'm invoking contact.new inside visitors controller.

when submit action executed, in contacts_controller user redirected root_path, in save or in error.

there email field used deliver user mail. setback happens when user doesn't fill , reason user redirected contacts_path instead of root_path.

it throws following error: an smtp address required send message. set message smtp_envelope_to, to, cc, or bcc address.

this function reads email , delivers user: visitormailer.landing_form_notify_user(@contact).deliver_now not filling redirects user contacts_index.

question: how can stop executing function if user hasn't filled email field?

app/controllers/visitors_controller.rb

class visitorscontroller < applicationcontroller   def index     @contact = contact.new   end end 

app/controllers/contacts_controller.rb

 def create     @contact = contact.new(contact_params)      respond_to |format|       if @contact.save         visitormailer.landing_form_notify_user(@contact).deliver_now         format.html { redirect_to root_path, notice: 'good' }         format.json { render root_path, status: :created, location: @contact }       else         format.html { render root_path }         format.json { render json: @contact.errors, status: :unprocessable_entity }       end     end   end 

app/mailers/visitors_mailer.rb

  class visitormailer < applicationmailer     default :from => "mygmail@gmail.com"      def landing_form_notify_user(user)          @user = user          email_with_name = %("#{@user.name}" <#{@user.email}>)          mail(            to: "#{@user.email}",            subject: "#{@user.name}" + ', hi.'          )     end   end 

if don't want attempt send email if email address missing, have check email address before call mailer.

 def create    @contact = contact.new(contact_params)     respond_to |format|      if @contact.save        unless @contact.email.blank?          visitormailer.landing_form_notify_user(@contact).deliver_now        end        # more stuff if save succeeds      else        # stuff if save fails      end    end  end