In Luminate Online, you can set an email status to Unknown to indicate that the system should again begin targeting an email address that was previously marked with a status of Bad (Hard Bounce). By marking the status as unknown the next time you target these email addresses, the system will attempt to deliver email to them, and mark the email status field according to the result.

To set an email status to unknown, follow these steps:
  1. Go to Constituent 360 > Constituents and search for the constituent you are concerned with. 
  2. Click to edit their record.
  3. Edit the email status so that it is Unknown, then save the change

Alternatively, you can also use a variety of 3rd party email validation tools to check email addresses in bulk or one by one. By searching Google for the term "Free Email Validation Tools" you can find several options to choose from.
Note: We provide links to third-party websites in an effort to help you resolve your issue. We are not responsible for the information on third-party websites, and we cannot assist with implementing the resolution from these websites.