Skip invalid emails when sending newsletter

We were seeing an exception when sending some emails due to having
invalid format

With this commit we are skipping this invalid formatted emails when
sending the newsletter

app/models/newsletter.rb

@@ -20,9 +20,41 @@ class Newsletter < ActiveRecord::Base
     sent_at.nil?
   end
 
+  def deliver
+    run_at = first_batch_run_at
+    list_of_recipient_emails_in_batches.each do |recipient_emails|
+      recipient_emails.each do |recipient_email|
+        Mailer.delay(run_at: run_at).newsletter(self, recipient_email)
+        if valid_email?(recipient_email)
+        end
+      end
+      run_at += batch_interval
+    end
+  end
+
+  def batch_size
+    10000
+  end
+
+  def batch_interval
+    20.minutes
+  end
+
+  def first_batch_run_at
+    Time.current
+  end
+
+  def list_of_recipient_emails_in_batches
+    list_of_recipient_emails.in_groups_of(batch_size, false)
+  end
+
   private
 
   def validate_segment_recipient
     errors.add(:segment_recipient, :invalid) unless valid_segment_recipient?
   end
+
+  def valid_email?(email)
+    email.match(/\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i)
+  end
 end