added mailer

app/mailers/application_mailer.rb

@@ -0,0 +1,4 @@
+class ApplicationMailer < ActionMailer::Base
+  default from: 'markus@hanflegal.ch'
+  layout 'mailer'
+end

app/mailers/supporter_mailer.rb

@@ -0,0 +1,6 @@
+class SupporterMailer < ApplicationMailer
+  def welcome_email(supporter)
+    @supporter = supporter
+    mail(to: @supporter.email, subject: I18n.t('welcome_email.subject'))
+  end
+end