Our company owns a one letter domain (e.g. "x.tld"), that follows a quite common sequence. A few months ago we've enabled receiving e-mails for all local parts on that domain.

We've received hundreds of notification mails, newsletter subscriptions, alerts (from internal systems disclosing details about infrastructure of giant corporations), etc.

It was quite fun, but became annoying quickly. We've then reduced reception to the common hostmaster@, ... mailboxes and for all other mailboxes we are now rejecting the mails with a nice reminder message in our Sieve filters.