Wayfair, even after contacting the manufacturer, was not able to answer my question about how the door operated--whether there was a limitation on the hinge that kept it from flopping open.  Our mailbox will be mounted in a brick pillar and the knob hitting the brick was an issue with the mailbox we are replacing.  This new mailbox has a limitation on how far the door opens, so it will not hit the brick pillar.  After receiving the mailbox, however, we have another concern:  the space underneath the handle to open the box has an opening which will allow spiders to hang out there and/or enter the mailbox.  Extreme wet weather also might allow dampness to enter the box.  We will be super-gluing a piece of plastic over the opening.  We bought this particular box because it was the closest in size to the one we are replacing.