'Print Receivables Transactions' Doesn't send the invioce to required email addresses

Hi,

When running the 'Print Receivables Transactions' process, the process ends successfully but an email isn't sent to the relevant contacts, although it is mentioned in the customer's account profile that the preferred delivery method is 'Email'.

Process Parameters:

Outcomes:

I'd like to know what is holding back the sending of the email, as we're using the vanilla bursting query for the invoice.

Thanks,

Guy