The Tx Address updates properly, but the interrupt associated with that mailbox (mailbox 2) still triggers on the default ID the CAN component was compiled with (in this case 0x601) and not the 0x6BE I set the register to. This leads me to think that the ID of an full Rx mailbox isn't used as a mask, or if it is, it's configured at compile or initialization time and not updated later.
Does anyone know how I can do this? Should I be setting the mask register somehow? Setting that register before I initalize the CAN componenet?