So the new multiple contact implementation is active now, and it leaves a lot to be desired.
Currently you can add multiple contacts to a customer or supplier and mark if each contact should receive invoices/purchases (which apparently also applies to all other document types too such as quotes and statements). The first contact, called the Primary Contact will always receive all documents.
There is no way to select which contact receives a document when sending it, you either mark the contact the receive effectively all documents, or none.
This is not helpful, most companies have different contacts for different documents. Sales guys for quotes, purchasers for invoices, accounts team for statements etc. There needs to be an effective way to select, at time of sending, who gets what document. The Primary definitely should NOT be receiving every document either.
I would suggest adding a field to the contacts section, so you can add a job title/function to each contact - sales, accounts etc for example. Then on the email screen when you send something like a quote, a drop down box in the email address field at the top that lists the contacts saved for that customer along with their job title, so you can select one or more contacts that will receive the document you are sending.