Many small organizations now have websites and provide an email address for customers to contact them. A simple HTML link of the form mailto:[email protected] is easy to implement (all popular HTML editors allow you to create this), and the results are easy to retrieve—they arrive in the user's mailbox.

The alternative to a mailto: link in a web page is to have a web form where the customer enters an email address and a message, and then submits the form. The data is processed by the web server and forwarded to the recipient. This is less flexible than an email—for example, attachments cannot be added. Additionally, the web form relies on the customer to enter their email address correctly. If this is typed incorrectly, then the customer contact will be lost.

From an early time in the history of the Internet, automated computer programs have tried to download web pages and follow links to other web pages. Typically, these spiders walk the Web to generate indexes for search engines...