My message response rate, formerly 100 percent, suddenly dropped to 67 percent because I didn't reply to a message from a *seller* about an item I bought that hadn't arrived yet. It was my understanding that messages from sellers don't have to be replied to and aren't calculated in the message response rate.
From the Dashboard/Star Seller Q & A section regarding messages --
''What messages count towards the message response rate?
Your message response rate is based on just the first message in a conversation, not ongoing conversations. This means you just need to respond to the first message within 24 hours. This applies to messages both from buyer and seller accounts.''
@Betsykitsch: "It was my understanding that messages from sellers don't have to be replied to ..." Unfortunately you understood incorrectly. The Star Seller metric is that the FIRST message of EVERY NEW thread must be replied to (or marked as spam) within 24 hours. It does not matter who sent it, the subject matter, if it is a duplicate or blank or anything else.