Tests not working. Not sure why.

app/models/virtual.rb

@@ -1,4 +1,16 @@
 class Virtual < ApplicationRecord
+    validate :domain_name_exists
     validates :email, presence: true
     validates :destination, presence: true
+
+    def domain_name_exists
+        if email.present?
+            if !email.index("@").nil?
+                split_email = email.split("@")
+                if !Domain.exists?(domain: split_email[1])
+                    errors.add(:email, "domain must be looked after by this server")
+                end
+            end
+        end
+    end
 end