@Temperdini: The Star Seller metric for messages is very simplistic and binary - either you replied to (or marked as SPAM) that first message of a new incoming thread within 24 hours or you did not.
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.
A controversial workaround : 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 (but not retroactively) if the original message was within the current star seller period. Note that subsequent messages from that account may go directly to the SPAM folder. Unless something has changed recently, you can only mark a message as SPAM using the buyer app or a browser, the option is not available in the seller app.
