Yes, BQE CORE does support automated emails sent to clients for past due or outstanding invoices. This feature works by automatically sending email notifications to clients, reminding them of outstanding payments. You can customize when these reminders are sent, choosing to dispatch them before the invoice due date, exactly on the due date, or after the due date has passed. This feature is turned off by default. To start using automated invoice reminders, you will need to enable and manage them through CORE by navigating to Settings > Billing & Invoices > Accounts Receivable. You can enable this option up at the client level as well as the invoice level.
You can also set up invoice past due reminders for yourself through User Settings > Reminders that show up later in the Reminders screen.