Marketo has a system smart list that finds duplicate people by matching their email addresses. If you want to use another field to find duplicates with, here's how.
Marketo is now standardizing language across all subscriptions, so you may see lead/leads in your subscription and person/people in docs.marketo.com. These terms mean the same thing; it does not affect article instructions. There are some other changes, too. Learn more.
1. Go to the Marketing Activities area.
2. Select your smart list, click on the Smart List tab.
3. Find and drag the Duplicate Fields filter into the canvas.
Choose one of four available options:
Done! Run the smart list to find people with the same value in the previously selected field.