The Poll Receive function confirms whether a successful reception occurred in the specified mailbox. Use the poll function also if using interrupts. Use it from within the receive interrupt, to check which mailbox received. If a message was received, call the Read CAN Message function which will write the message data to the given address. The function notifies the user in the return value if a CAN message was overwritten if the mailbox is seldom read. This can be of interest if data needs to be received in a certain order.