It's our 8th Christmas in our "new" house".
Surely all who matter would know by now that the people who used to live here have a new address.
Yet we still get random mail for them and just got another card. It's annoying.
They live close enough so when MrZing does Sat shop he makes the effort to swing by and drop things off but honestly I think he's been courteous for long enough.
So I'm considering options and wondering what you actually do in a similar situation with such mail:
A, suck it up and pass it on as until the end of times. perhaps notify The Guinness records panel for a potential entry.
B. chuck it
C. open it and display it nonchalantly
D. open it to see if there's cash in it, keep cash, destroy all evidence
E. return to sender (I don't actually know how)
F. send a Christmas card from us
G. some other solution