This is also the second time I have had someone make a first post and then had no response to my reply. Even though I had replied quickly. Their email should be correct if they have just joined

Usually you would be excited to get a response and be checking, I would be.
I think the three posts for a personal message is confusing to new people. We also use acronyms like PM! Guilty. Do they even know where the PM button is?
This may be all in the guide for beginners, but maybe it needs to be more obvious.
I even said hit the reply button and my post is above it. Just like this one.