Why didn't a buyer receive my reply to their question? They then left negative feedback for no reply

[apowens]

The buyer received the item, but sent me a message saying there was no paperwork. The listing didn't include any paperwork which I explained in a reply. I then received negativefeedback for not replying. 

I n the message thread was a note from ebay  "Your buyer has reached out about their order. Since you used Simple Delivery, we'll work with your buyer directly on any delivery related questions."

Does this mean that buyers may not be receiving replies after delivery??

[john1297576]

That reply from ebay is a standard meaningless reply, it just means buyer has contacted you or opened a case.

Did you check that your reply was sent? Does it show in messages sent, or as a reply on the message received, it is very easy to forget to click send.