Plesae add the below enhancements when emailing bulk invoices from the invoice screen:
1. Show the customers email address that is being used so that it can be checked quickly for all invoices before approving
2. Allow "send me a copy" to be selected
3. Allow the subject to include the invoice number similar to when emailing an individual invoice rather than having a standard subject for all invoices
4. Allow a default message rather than entering a message each time you send bulk invoices