Drop a leaflet royal mail

A classic British phrase!

To "drop a leaflet" is a colloquialism that refers to the act of delivering a leaflet or brochure through the mail, typically by the Royal Mail postal service. In other words, it means to send a promotional or informational piece of paper to a large number of people, usually through a mass mailing.

The phrase is thought to have originated from the practice of literally dropping a leaflet through a letterbox or onto a doorstep, rather than posting it through the mail. However, in modern times, leaflets are typically sent through the post, and the phrase has become a common way to refer to this type of mailing.

So, if someone says "I'm going to drop a leaflet," they mean they're going to send a leaflet to a large number of people through the post, often as part of a marketing or promotional campaign.