Religious Junk Mail

Question

We continually receive junk mail (actual mail not email) from religious organisations, yeshivot etc (requests for money, flyers for campaigns etc) . Often they include quotes from the tanach in their promotional material or even sometimes prays, or little tefilact haderech cards or the like. Our post box is always spilling over with this type of mail (we often only collect our mail once a week). Am I obligated to sort through it all to extract items like this or can I throw it all out without checking? If I have to check, what needs removing and what can be thrown out.