You seem to be missing the whole point that you maintain customer email addresses on their customer card.
If you change an address, MYOB then sends a reminder email to the last email address that was used, which is NOT the current address.
Similarly if you need to email an invoice to someone internally, MYOB then sends them a reminder. I've had to instruct staff to print to PDF, save a copy and then email to other staff, which is one more step than it needs to be since there is an email invoice function in the software.
It's great that there is this functionality to save time on manually sending reminders but there's still a huge flaw in the way it works. If you store customer email addresses on their card, why would this not be referenced for the reminder emails??