Spam emails can be one of the biggest annoyances on the internet. Whilst there is no complete way of stopping them, using the Askimet plugin should massively reduce the amount you get.
1. Firstly go into the backend of your smartsite. In the dashboard click 'Contact' > 'Contact Forms'
2. Click on your contact form and in the Form tab, click reCAPTCHA
3. You will be shown a pop up that will allow you to install a Captcha block. Click the link in the text.
4. From here you will be taken to the Contact Form Recaptcha guide.
You can follow the steps on there or below.
Copy the key pair into the WordPress admin screen of the site you registered.