In this document we’ll go over some of the ways to reduce/prevent spam making its way through Inbound Forms. You can combine these methods for best results.
Add the Honey Pot field
Activate and enable Akismet filtering
Inbound Now provides an extension that adds a Google reCaptcha field as an available field type. Activating this extension and adding a ‘Google reCaptcha’ field to your Inbound Form will require form submitters to solve the Google Captcha before submitting.