I think it is not needed to respond to messages which Fiverr automatically detects as spam and informs that it will not affect the response rate. And if you get a message which seems to be spam, it is supposed to be your responsibility to mark it as spam.
When I find a message that seems to me as spam but not detected by Fiverr, either I reply informing Fiverr TOS or mark it as spam or do both. Is it the right way to address these kind of messages? Please let me know if I make any mistake in the way of responding to messages.
Thanks and best regards,
Carolinamaria