Combined Mailing of Invoices & Statements or Multiple Invoices

It saves a lot of time if you can send a client a statement and automatically include all outstanding invoices at the same time and being able to mail multiple invoices at the same time to a client. We have multiple services and items we invoice to clients and clients prefer to invoice for each service as it happens, therefor we have multiple monthly invoices and ad-hoc invoices. We then send out monthly statements with outstanding invoices. Many clients also request all their invoices for the year, for compliance purposes therefore if a mailing option can include multiple invoices and statements.