After installing this mod, a small box is displayed above each article, in which an email address can be entered. After clicking the "GO" button, a PDF will be created from the articles and sent to the entered email address.
The created PDF lists all articles. The top of the PDF contains your forum name, linked with your forum. Each article is linked with the article in your forum too.
The download package, which you can download from this page, contains a mod for the phpBB forum version 2.x and 3.x. Each version contains an install instruction in phpBB style.