Email harvesting is the process of obtaining large number of email addresses through various online sources. They obtain email lists, either by purchase or theft, of valid email address for the purpose of sending bulk emails or Spam.
Spammers harvest email addresses through various techniques, including:
- From mailing lists
- From Web pages
- From a Web browser
- From Internet relay chat and chat rooms
- By buying lists from other spammers
- By hacking websites
The most common method of email harvesting is when Spammers use specialized harvesting softwares known as harvesting bots, or harvesters. Spammers may use bots to find valid email addresses on the internet by spidering web pages. The CAN-SPAM Act of 2003 made it illegal to harvest address via automated means. It is illegal to sell or give away lists of recipients gathered for legitimate purposes.
The following techniques can be used to prevent email harvesting:
- Prompting users to enter a correct CAPTCHA before disclosing the email address.
- Using a CAN-SPAM notice enabling prosecution of spammers under the CAN-SPAM Act of 2003. The website administrator must post a notice that "the site or service will not give, sell, or otherwise transfer addresses maintained by such website or online service to any other party for the purposes of initiating, or enabling others to initiate, electronic mail messages."
- By monitoring the mail server. This method can be implemented at the recipient’s email server. It rejects all email addresses as invalid from any sender specifying more than one invalid recipient address.
- Using a spider trap. This is a part of a website built to combat email harvesting spiders.
- Create a graphic that has your email ID written on it. Since the bots cannot read the graphic at this point, your ID will be safe.
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