Whether you're replacing an old mailbox or installing a brand-new one, setting the post in Quikrete will keep it standing steady in rain or shine. Even better? With this fast and fun curb-appeal project, you can altogether skip the ordeal of mixing cement. Simply drive the mailbox post into a hole filled with Quikrete All-Purpose Gravel, then top with Quikrete Fast-Setting Concrete and water. Allow four hours of drying time before attaching the mailbox. See for yourself how quickly this project comes together by watching the video walk-through.