We are getting rid of your mail problem once and for all!
Take a shoe box, preferably with attached lid. Write your name on it in big letters with a marker. Repeat for other household members who receive significant mail. One box per person. Keep boxes in a cabinet near where you regularly place your mail or switch to nicer boxes if you need to keep them out. Everyday, when you take your mail in, immediately sort it. All junk mail goes directly into recycle. Catalogs and periodicals go into designated boxes (once again start with a shoe box for now and switch later). All other mail, place into the box of whom it is addressed to. DONE! You now know where all your mail is for when you are ready to answer invites, pay bills etc. For practice, go to the pile of mail on your kitchen counter, radiator near the door, dining room table and try it. Let me know how this system works for you. As with everything, this is about establishing a routine and it can take practice. After sticking to it for a few days, it can become second nature.