How to find duplicate Leads in the Leads module AND/OR in the Contacts module

How to find duplicate Leads in the Leads module AND/OR in the Contacts module

How to find duplicate Leads in the Leads module AND/OR in the Contacts module


I need to clean up a small database of 2000 leads and 300 contacts before adding 4000 more leads.

How can I quickly identify if there are ANY duplicate emails in Leads or Contacts?
Thank you.
George