To use Addressfinder's Bulk Email Verification service, export your emails into a CSV file. Upload that CSV file into the Addressfinder Portal > Bulk Cleansing page, select the column the emails are in and start the process. The service will take each email address and run them through a series of checks to ensure they are able to receive email. The results of these checks will be populated into the CSV file in columns appended to the original data. The data populated will include the full verified email, the type of email it is and, if unverified, the reason why the email was not verified.
On completion, you will be invited to download the completed CSV file and then import the clean data back into your database.