SO Ack. / Invoice email break routing

Migrating Altec to Advance Print and Docstar.

It appears that the email address for both the Sales Order Ack. and the Invoice come from the customer email record.
The contacts are many times different. Anybody using multiple emails? I would assume that we could set it up using Customer Contacts, but it does not seem that way.

I am extremely light on knowledge when it comes to reporting, but our report guy has modified the standard Invoice. There is a relationship between the Customer.PrimBCon (Primary Billing Contact) and the Contacts table. We get the Invoice email address from this calculated field.

I am learning APR with Docstar and stumbled on this today.

When I was looking at this a while ago the only thought I came up with was a custom field that stored the multiple contact email addresses separated by a semicolon and creating a BPM that when ever a customer was updated the custom field would update in case of any changes.
Also you would have to initially populate the custom field via DMT etc.
Then in Advance Print just put that field in the To box.

@reond yup - that is exactly how we have done it