In the last year or so our mail is consistently misdelivered to our neighbors and vice-versa. It’s very likely the reason why we missed the deadline to pay for her benefits this past summer and why we keep missing important stuff and/or have to request original senders to resend stuff. What a pain in the ass.
Robin did a search on the web and found others with similar problems. Check out this great thread:
I want my snail mail! (via Ask MetaFilter)