Reminders for overdue invoices can be emailed to debtors automatically. When you create reminders, an email is sent with the reminder in PDF format as an attachment. This requires you to have a valid license for External documents, and to configure settings in the Document delivery method section in Isah. In that section, you register things such as the recipients of the reminder email. Use the Communication tab of the customer contact and/or the employee to sign up additional contacts for reminders. See also the Help information on Reminders.
If you have specified in the delivery method settings that the reminders must be linked to the debtor (the Link report to entity check box is selected), then in Isah, you can click the Documents button on the Customers form to view all reminders sent to the debtor.