In the latest version of OptimizePress we have hardened the form processing for OptimizePress Opt-in forms to help protect against spam signups.
If you are seeing spam signups or spam email addresses/names in your email list, and would like to take further steps to prevent those, you may wish to install our anti spam plugin, an invisible reCaptcha for opt-in forms. Download the plugin here:
Setting up the Google reCaptcha plugin:
1. Install the plugin.
2. Once installed, get your free "Sitekey" from Google Recaptcha:
3. Fill out the form in Google Recaptcha page. Make sure to tick the box for the invisible recaptcha. 
4. Click your newly created label to access the API keys.
5. Copy the Site key and Secret key.
6. Go to OptimizePress >> Google ReCaptcha and paste your keys there. Save when done.
7. Finally, clear your element cache under to OptimizePress >> Support >> OptimizePress Cache. That's it.
Note that your users only need to do the recaptcha once because the system has features to remember that a certain user is bot or not.