Akismet is an advanced hosted anti-spam service that fights the latest and dirtiest tactics embraced by the world's most proficient spammers. It's a great Spam Control service that has a free plan which you can use to stop spam coming from your ContactUs.com forms. Click here to learn more about Akismet.
If you've already signed up with Akismet go for your API Key and follow the instructions below. If you haven't signed up with them, go ahead and sign up here: https://akismet.com/signup.
After completing the fast signup process, you'll see this confirmation message:
Make sure to copy your new API Key so you have it handy. Now that you have an Akismet API Key, follow these steps in order to add it to your ContactUs.com forms:
1. Login to your ContactUs.com account and go to the "Forms" Panel. Select the form that needs the Akismet API Key.
2. Click on "Form Settings".
3. Turn the "Akismet Anti-Spam" button "ON".
4. Paste your API Key on the designated field that will show after turning the button on.
5. Save & Publish the changes.
That's it, you are now safe from spam! Akismet will check for spam in the email and text fields so you don't receive unreal submissions.