The term "junk mail" found its way to these isles from the United States in the 1960s — the words were first uttered in parliament in 1964, in a debate about the Post Office's new Household Delivery Service (that is, the delivery of door-to-door items). The new service was introduced after private companies had started delivering circulars and handbills to householders on a fairly large and increasing scale. It appears that the "junk mail" label was mainly reserved for this specific type of advertising mail.

Circulars and handbills were by no means new; they date back to the 17th century, when trade cards started to appear. These cards were nothing like the cheap business cards posted through your letterbox nowadays; they were larger and rather elaborate. They also weren't delivered door-to-door yet. It is not quite clear exactly when letterbox spam started but, thanks to William Smith, we do know that "bills" were being delivered in the 19th century — even before letter boxes had become common (errand boys use to shove adverts under the door or leave them under the door knocker).

Junk mail in the UK peaked in the mid-2000s, so much so that it became one the most common nuisances. It became a political issue as well. For a while it looked like Defra would force the junk mail industry to clean up its act and that the government would finally ban the sale of the electoral register. In the end, nothing of the sort happened. Instead, junk mail volumes gradually declined as advertisers moved their budgets to online advertising. Junk mail would hit the news headlines a few more times, for instance when the aggressive marketing tactics common in the charity sector were exposed, but by and large the junk mail issue has disappeared.