Bitcoin core will reject and transaction with an "absurdly high fee". This means that it will not accept it to the mempool and will not relay it. I don't remember what the exact threshold for this is, but I think it is actually fairly low.
AFAIK its still accepted and relayed, its just refused if you create a TX with a fee over x*min_relay_fee or 0.1 BTC. Not exact numbers just from memory.