RE: Technical Issues in Forums post from 3 weeks ago: https://community.etsy.com/t5/Technical-Issues/UPDATE-Messages-appear-to-not-send-when-responding-fr...
Apparently this issue is still not resolved. I have had 2 instances this week (beginning Sunday, 7/24) where my messages to customers did not appear to have been sent. In addition, I was expecting a reply from these customers, which I have not gotten. The only response I've received was an automated message from Etsy telling me that if I didn't respond promptly, the customer could open a case against my shop.
Please look into this ASAP!
This is a seller peer to peer forum and not a way to contact Etsy if that is your hope. Have you checked your "Sent Messages" folder in Etsy Messages to see if your reply did or did not get sent? Remember that most messages with an account are now being lumped into a single thread so it may take a little more searching.
Did the information append itself to an old message from the same person? If you have an order from them, did you look at the order to see if the response was listed there.
The other issue may be to clean out cache and cookies and have a new cookie placed. Old information may be interfering.
One of the messages attached itself to the customer's order. The other did not. I have also tried starting a new message thread with the customers, and have had not response from either of them indicating that they received any message from me.