Merge commit from fork

* Disallow some special characters in e-mail addresses

* Add size limit to email columns

app/validators/email_address_validator.rb

@@ -11,8 +11,14 @@ class EmailAddressValidator < ActiveModel::EachValidator
     value = value.strip
 
     address = Mail::Address.new(value)
-    record.errors.add(attribute, :invalid) if address.address != value
+    record.errors.add(attribute, :invalid) if address.address != value || contains_disallowed_characters?(value)
   rescue Mail::Field::FieldError
     record.errors.add(attribute, :invalid)
   end
+
+  private
+
+  def contains_disallowed_characters?(value)
+    value.include?('%') || value.include?(',') || value.include?('"')
+  end
 end