This plugin add custom validation messages to individual fields of your contact form 7. You will be able to add your custom error message for text, text area, email, url, radio, phone number etc fields in contact form 7. Features of this plugin. Add Custom Validation Message to Contact Form Fields. Allows field to be validated for text, text area, email, url, radio, phone number and more. Error message for individual fields. You can add custom validation with multiple forms.