We have created a Drupal Form integration package, that will perform verification of email addresses being used to sign up or register on a Drupal website. This has been written for, and tested with Drupal version 7.

Download and Install
1. Download the integration package from here: drupal7-emailchecker-v1.0.zip
2. Upload to your Drupal web host, extract it and place it under sites/all/modules/. For example, if /var/www/html is your web server document root, unzip unto /var/www/html/sites/all/modules/
3. Enable the emailchecker module (/admin/modules).

4. Go to the emailchecker configuration form in your Drupal instance
4.1 API Key => Place your API access key (visit https://login.emailchecker.com/?api to get a trial key)
4.2 Form and Field Details => Configure your form and fields; they should be in the “form_id|field_id” format.

For example:

4.3 Enable Log => Enable logging for your results.

Your form will now automatically be integrated with the emailchecker.com verification API.