Data Management -> Tasks -> Task List -> Create New Task -> Invalid Email
 
  1. From Data Management select Tasks
  2. Click on Task List tab
  3. Click Create New Task
  4. Select Invalid Email from the Task Type list
  5. Provide a name for the task
  6. Provide a description for the task
  7. Set the task to Active YES (defaults to NO).*
  8. Select "The last e-mail was undeliverable due to a 'hard' bounce." (selected by default)
  9. Choose when the task should update (default is weekly).
  10. Save the task.
A group will automatically be generated with the same name as the name provided for the task in step 5.