Just as a matter of professionalism, and courtesy, I've always tried to leave as little (or no) mail for anybody who is working the next day after me... when I was a sub, my Reg would always come back and thank me for taking way more phone books than they had imagined that I would... I never left sets of box holders for anyone... unfortunately, since I've been a Regular, I've had several subs that seem to think their goal in life is to deliver the absolute minimum mail that they can get away with... and that's included not taking phone books, nor boxholders when they can get away with it... to me, mngt allowing this is just encouraging a poor work ethic among future carriers and making a less professional and courteous working environment...I’m a rural sub. My reg tells me to leave whatever I don’t feel comfortable taking/doing. I try to leave her nothing!
Ask yourself how you would like to be treated, and then try to treat others that way... if you wouldn't like mail left for you, then don't leave it for others... just sayin'... not rocket science here...