You can schedule email notifications 3 ways: in an invoice; within a recurring invoice; or from the collection center.
Send from an individual Existing/Open Invoice
Open an invoice that has a balance due and in the Options Menu you can choose to Send/Schedule Invoice Email.
In the next screen you can change the radio button at the bottom to Schedule For Later
This opens new options for frequency to schedule the email.
You can choose On A Specific Date; X Days Before/After the Due Date; or Every X Days
Edit a Recurring/Future Invoice
Go to the Recurring Invoices module, click into a Recurring Invoice. In the right of the screen there is a checkbox to "Send Emails Based On Due Date". Checking this box will show a dropdown to choose to send the email Once, or Every. If you select the Every option then you choose how often the email will be sent and when (before or after the due date) the email starts sending. **This only affects the next/future invoices created.
Schedule from Collections Center for Multiple Existing/Open Invoice(s)
To send from the Collection Center you can select multiple invoices using the checkboxes in the first column.
This will show new options at the top of the screen. Select the Send/Schedule Email button to schedule emails for all invoices you selected.
You have the same options to Send Immediately or Schedule for Later.
After you have scheduled emails to be sent you can see them as "Pending Emails". From the Collection Center there is a column on the right side of the screen for Pending Emails. This will show how many emails are scheduled to be sent for that invoice. NOTE: a scheduled email can be setup to send every x days; it will show as 1 scheduled email.
Email History Report
There is a report that will show All Pending emails. Go to the Reports - Email History and change the dropdown in the top right to All Pending Emails.
From this screen you can Cancel a scheduled email using the x on the right side of the screen. You can also cancel multiple scheduled emails by selecting them with the checkbox or with the Select All button at the top of the screen.
You can also see and cancel scheduled emails from within the invoice screen itself.