IMR or Invoice Message Response messages give detailed feedback to your supplier about the electronic invoices you received. These messages are sent automatically based on certain actions you take in Billit.
You can compare an IMR message to a reading confirmation or a blue checkmark in WhatsApp. Although it gives much more insight than a regular reading confirmation.
Besides IMR messages Billit customers can also receive MLR or Message Level Response messages. These MLR messages give you technical feedback from the Peppol network. As Billit user you don't have consider the differences betwee these two messages. You will receive the different messages in a clear overview in the message section of the invoice detail page.