Messages to providers

I have sent some messages to providers, did not receive a reply and they show unread. Do they have to send conformation to show they read them? Or have they still not read them?

This happens to me as well. My guess is they have not been read. I don't know what there deal is. I guess they don't want our business.

It's possible that they just haven't been read as of yet.

But also, you don't have to click on the "okay" confirmation either ....which would show the PM as unread.

Thanks If they haven't responded then must have no interest.