At present if you raise several invoices for the same customer when you come to creating a pdf to email the invoices it will amalgamate all the invoices in one document. However more and more customers now request one email with separate pdfs for each invoice. The only way to do this at the moment is to click on each individual invoices and export each one, then when they are all saved you can email them as separates Pdfs it is extremely time consuming.
However for such a new feature to work, the name of each pdfs should feature the invoice number otherwise the customer will end up having x invoices with the same name....!