That started happening to me a week or so ago and I discovered that the auto emails from RRB are now coming in with the "inquiry@ratrodbikes.com" email address. If you look in your Junk Mail box, you will probably see the emails there.
All you have to do is find the section in your email program of choice that allows you to "whitelist" email address and add the inquiry@ratrodbikes.com address there.