1. From the master list of your invoices, look-up the payee name so that the result is filtered. Then tick the checkbox on those invoices you wish to process, or simply click on the Select All checkbox from the top. 
2. Click on the down arrow on the checkbox at the top, and click on Send overdue Email.
3. A pop up will be shown and click OK to send the overdue email.
4. Before you send an overdue email, please make sure that the invoices filled with email.