Multiple email addresses for customers#17

Hello - I need to record multiple (two in fact) email addresses for a customer, so that when I create an invoice for that customer it is sent to both addresses. They have one main mailbox and another one which is also monitored, but invoices keep getting missed for a variety of reasons. Sometimes they go into spam, other times the person who looked after the main mailbox was on maternity leave, etc.

Anyway, I’d like to ensure invoices are paid, and if sending them to multiple addresses ensures that, it would be a big help.

Thank you.