Hi, you could use follow-up reports to send the customer his invoice and payment information. https://www.odoo.com/documentation/16.0/applications/finance/accounting/payments/follow_up.html

Use the "print" option first, to see what the customer will receive. It will show all pending invoices with their amount due:

You could also use partner ledger:

And finally you could go to Accounting - Journal Entries - Filter by partner, select all the invoices and select Print - Invoices:

If you need something more "Peachtree like", where the invoices, payments and aging is shown, you would need to be running Odoo.sh / Onpremise and install an app such like this one: https://apps.odoo.com/apps/modules/16.0/sh_customer_statement/

Cheers,

Carlos Mendoza