Which of the following is illegal:
(1) Scrape emails from a site and send one email to each address.
(2) Scrape emails from a website and sell them.
(3) Make a scraping script and sell it without using it.
Note: The target website Terms of Use (ToU) state that no one can crawl/scrape it.

My answer to this question:

1. No one knows how you get email addresses from a target website. You might have manually visited each single page of the website and copied emails. After that you’re free to send mails to each address (and not just one). Semi-legal

2. When you sell, that which you’ve scraped, a buyer might abuse the email addresses and at a court your name will immerse. Many legal consequences. Illegal

3.  You develop a scraping script and all the legal consequences fall on a script user. Similar to the weapon manufactures: they produce guns, yet those who abuse them (eg. kill with guns) are taken to courts and might be sentenced. Legal

Read more of the scraping legal issues and consequences.