Why must I answer this question?
The aim of this check is to protect the owner of the e-mail address from receiving unsolicited e-mail.
Although spammers can rent or buy existing e-mail lists, many opt to use software known as 'e-mail harvesters' (often referred to as 'spam bots') that extract e-mail addresses from web pages. These e-mail harvesters work very much the same way search engine spiders do and try to collect every e-mail adress they encounter on the web. However, the brute force algorithms they use, are not able to answer the simple question above.