Account Collaboration - Multiple email address for outgoing business documents

Hi,

Is it possible to specify multiple recipient email addresses for outgoing business documents?

For example, we would like to automatically send our Sales Invoices to two customer email addresses. However, we find when we maintain the customer account in Communication - Collaboration we are only able to input 1 email address.

I'm aware you can add additional To, CC, BCC addresses by adjusting the output settings at the point the document is created, but this isn't efficient.

Lee