@GraceAMano: "Please fix this--thanks!" Just so you know, even if Etsy Support or the Help Pages sent you here this is a seller peer to peer forum, and should not be considered a way to contact Etsy, if that is your hope (although Etsy does sometimes read and reply to posts).
As others have mentioned and as it says right on your Star Seller page and elsewhere, you need to reply to the FIRST message of EVERY NEW INCOMING THREAD within 24 hours. It does not matter who sent it, the subject matter, if it is a duplicate or blank or anything else. If it is SPAM then it should be marked as such.
"... auto-reply ..." : An auto reply would be in response to a message you sent and would not count against you for Star Seller, and Etsy has no official way for a seller to send automated Etsy messages.
If the unanswered new thread is not a Help Request, at least for the time being, it appears that marking an unanswered new thread as SPAM (even after the 24 hour deadline has passed) will cause your reply percentage to change in a day or two if the original message was within the current star seller period (but not retroactively). Note that subsequent messages from that account may go directly to the SPAM folder.
