I try to post message for items for sale but never find a response and my inbox never shows any messages sent. How do people sell anything if messages can't be sent or received?

Can you see your advert in the classifieds section after you have posted? If you can see them then so can others. If you cannot see them, there is a problem. I cannot see any classified ads of yours at the moment.
If this was for past ads that are deleted after some time, then maybe no-one has responded to your adverts. Just a thought.

I was responding to an ad not placing one

not for first time
my inbox shows nothing sent or received

We have just adjusted and updated our code. It should improve the acceptance rate of classified responses that are sent in email form to the original poster.

Thanks for your patience with this bug fix. Further improvements to the system will be made soon.

Please inform xiaococo that I am interested in the oven and mixer
Thanks