You see all these videos showing the work order lifecycle in FS365 and not one of them shows the act of emailing the invoice to the customer!
HOW THE FRICK CAN YOU EMAIL AN INVOICE TO A CUSTOMER with FS365 OOB???
You shouldn't have to export the Invoice template to a file then go to the customers timeline and send an email and add the attachment you just downloaded. The stinking data is in the database. You should just be able to hit a Email Invoice button to have FS365 create the PDF in background and send it out using the invoice template!