CAN transmit acknowledged even though no receiving node.

I want to set up error handling for my CAN messages, and I wanted to start with errors from sending messages to IDs not on the CAN bus net. However, every message I send is acknowledged. There is only stm32 chip set up on the net and the rest are currently TMC Pandrive motors. 
I am sending messages to individual motors with different IDs without issue - they're received and the motors react accordingly. 
So I am not sure how or why these messages to other CAN IDs are acknowledged. 
Below is the code I use in my CAN interface file. 

#include <CANInterface.h>

CAN_RxHeaderTypeDef rxHeader;
CAN_TxHeaderTypeDef txHeader;
std::vector<uint8_t> canRX(7, 0);
CAN_FilterTypeDef canfil;
uint32_t canMailbox;

void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan1) {
	std::vector<char> sendBuf(60, 0);
	uint8_t bufLen = sprintf(sendBuf.data(), "response triggered\r\n");
	HAL_UART_Transmit(&huart5, (uint8_t *)sendBuf.data(), bufLen, 200);
	HAL_CAN_GetRxMessage(hcan1, CAN_RX_FIFO0, &rxHeader, canRX.data());
}

void sendCANMessage(uint8_t component, std::vector<uint8_t> canMessage) {
	txHeader.StdId = component;
	HAL_StatusTypeDef status = HAL_CAN_AddTxMessage(&hcan1, &txHeader, canMessage.data(), &canMailbox);
	std::vector<char> sendBuf(60, 0);
	uint8_t bufLen = sprintf(sendBuf.data(), "status: %d\r\n", status);
	HAL_UART_Transmit(&huart5, (uint8_t *)sendBuf.data(), bufLen, 200);
}

void CANSetup() {
	txHeader.DLC = 7;
	txHeader.StdId = 0x02;
	txHeader.IDE = CAN_ID_STD;
	txHeader.RTR = CAN_RTR_DATA;
	txHeader.TransmitGlobalTime = DISABLE;

	canfil.FilterFIFOAssignment = CAN_FILTER_FIFO0;
	canfil.FilterIdHigh = (1 << 5);
	canfil.FilterIdLow = 0;
	canfil.FilterMaskIdHigh = 0;
	canfil.FilterMaskIdLow = 0;
	canfil.FilterScale = CAN_FILTERSCALE_16BIT;
	canfil.FilterBank = 14;
	canfil.SlaveStartFilterBank = 0;
	canfil.FilterActivation = ENABLE;

	HAL_CAN_ConfigFilter(&hcan1, &canfil);
	HAL_CAN_Start(&hcan1);
	HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING);
}