If you're trying to find contacts with a bad or an invalid email addresses in order to clean up your database, you will need to:

Go to the Contacts Tab and filter by Email Deliverability 

From here you can select from the following choices


  • Create a saved filter after applying, this way your contacts remain in your database and you don't risk re-importing them with a new list.
  • Remove these contacts from your list by selecting Actions > Delete Contacts

Related: How do I see which contacts do not have email addresses?