Managing the mass of emails in my inbox

I am notoriously bad with keeping up with my emails. However, I have learned one trick that really helps. I have created various folders to organize things that I do not need to read on a regular basis, but might need later. For instance, whenever I make an online purchase or sign up for an email newsletter from a site, I will then get numerous emails from that company. Many of those emails I really only use when I want to make another purchase and want to see what coupon codes they might have available now. So what do I do? I have my yahoo filters set up to automatically put those emails into the correct folder. I have folders for: Shopping coupons, Coupons and Contests, To Do, etc. This helps my inbox not be so full and directs mail to where I can get to it later. Hope this helps!