implement prototype of invalid emails data parser

lib/tasks/collect_invalid_validation_contacts.rake

@@ -0,0 +1,38 @@
+namespace :collect_invalid_contacts do
+  desc 'Starts collect invalid validation contacts'
+  task all_domains: :environment do
+    Contact.all.each do |contact|
+      result = Truemail.validate(contact.email, with: :mx)
+      unless result.result.success
+        collect_data_for_csv(contact, result.result)
+      end
+    end
+  end
+end
+
+def find_related_domains(contact)
+  Domain.where(id: contact.id)
+end
+
+def collect_data_for_csv(contact, result)
+  domains = find_related_domains(contact)
+
+  headers = %w[
+    contact
+    domain
+    error
+  ]
+
+  CSV.open('invalid_email.csv', 'w') do |csv|
+    csv << headers
+
+    domains.each do |domain|
+      attrs = []
+      attrs.push(domain)
+      attrs.push(contact.email)
+      attrs.push(result.errors)
+
+      csv << attrs
+    end
+  end
+end