Easy enough to install on my vinyl sided house.  Rain does get into the mailbox and collect at the bottom.  The two drain holes are tiny and don't allow all of the water to drain out.  I tried to drill larger holes and my drill bit didn't do anything more than scratch the paint, so I put some small gravel in the bottom of the mailbox so that my mail doesn't sit in a pool of water.  I like the looks of the mailbox, though.