Add email description to epp responce on contact creation

app/models/concerns/email_verifable.rb

@@ -0,0 +1,89 @@
+module Concerns
+  module EmailVerifable
+    extend ActiveSupport::Concern
+
+    def email_verification
+      @email_verification ||= EmailAddressVerification.find_or_create_by(email: unicode_email,
+                                                                         domain: domain(email))
+    end
+
+    def billing_email_verification
+      return unless attribute_names.include?('billing_email')
+
+      @billing_email_verification ||= EmailAddressVerification
+                                      .find_or_create_by(email: unicode_billing_email,
+                                                         domain: domain(billing_email))
+    end
+
+    class_methods do
+      def domain(email)
+        Mail::Address.new(email).domain&.downcase || 'not_found'
+      rescue Mail::Field::IncompleteParseError
+        'not_found'
+      end
+
+      def local(email)
+        Mail::Address.new(email).local&.downcase || email
+      rescue Mail::Field::IncompleteParseError
+        email
+      end
+
+      def punycode_to_unicode(email)
+        return email if domain(email) == 'not_found'
+
+        local = local(email)
+        domain = SimpleIDN.to_unicode(domain(email))
+        "#{local}@#{domain}"&.downcase
+      end
+
+      def unicode_to_punycode(email)
+        return email if domain(email) == 'not_found'
+
+        local = local(email)
+        domain = SimpleIDN.to_ascii(domain(email))
+        "#{local}@#{domain}"&.downcase
+      end
+    end
+
+    def unicode_billing_email
+      self.class.punycode_to_unicode(billing_email)
+    end
+
+    def unicode_email
+      self.class.punycode_to_unicode(email)
+    end
+
+    def domain(email)
+      SimpleIDN.to_unicode(self.class.domain(email))
+    end
+
+    def punycode_to_unicode(email)
+      self.class.punycode_to_unicode(email)
+    end
+
+    def correct_email_format
+      return if email.blank?
+
+      result = email_verification.verify
+      process_result(result: result, field: :email)
+    end
+
+    def correct_billing_email_format
+      return if email.blank?
+
+      result = billing_email_verification.verify
+      process_result(result: result, field: :billing_email)
+    end
+
+    def process_result(result:, field:)
+      case result[:errors].keys.first
+      when :smtp
+        errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_smtp_check_error'))
+      when :mx
+        errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_mx_check_error'))
+      when :regex
+        errors.add(field, I18n.t('activerecord.errors.models.contact.attributes.email.email_regex_check_error'))
+      end
+    end
+  end
+end

app/models/epp/contact.rb

@@ -77,7 +77,10 @@ class Epp::Contact < Contact
         [:email, :invalid],
         [:country_code, :invalid],
         [:code, :invalid],
-        [:code, :too_long_contact_code]
+        [:code, :too_long_contact_code],
+        [:email, :email_smtp_check_error],
+        [:email, :email_mx_check_error],
+        [:email, :email_regex_check_error]
       ],
       '2302' => [ # Object exists
         [:code, :epp_id_taken]