If you wish to significantly reduce spam submissions without interfering with your visitor's experience, you can enable what is called a honeypot. These are a series of hidden fields which only spam bots will see which, if filled in, will not allow the form to be submitted.
To enable this functionality for a Forms page:
- Navigate tot he Forms Manager
- Click Form Manager
- Open the form whose button you wish to customize
- Click the Options tab
- For Honeypot, choose On