Current solution:

If you mark sales invoices in the list and use the "Print" action, then sometimes not all sales invoices are printed. If you only use the "document layout" for setting up different email addresses, Microsoft suggests me to create a different report ID (other to that one set up in the report selection for the invoice) for those records. In this case my customers do not wish to have a different document layout so this is why I do not have another choice than to enter the different email address in the "document layout" table.

Suggestion:

All marked sales invoices should be printed, not matter whether the report ID is the same or not.