If a supplier sends an e-invoice to you as recipient but you get an e-mail with a PDF-invoice attached, it is because the e-invoice has been converted into a PDF-invoice. This is because your account with InExchange has a recipient service for PDF activated.
This recipient service does not mean that you can receive e-invoices, but that suppliers can send an e-invoice to you, that is converted to a PDF on the way and sent to the address specified in the activation of the service.
This is because it requires an ERP-system with functionality to manage e-invoices that are connected with InExchange invoice flow for it to work to receive e-invoices immediately.
Do you want to know if your ERP-system can receive e-invoices, you need to contact your system supplier, and then contact your Key Account Manager at InExchange or the support (0500-446360) to discuss a possible connection for receiving e-invoices.