You open your email and see a flood of messages advertising free consultations, deals, “breaking” news, and a whole bunch of other unwanted information. You didn’t ask for it, so why is your inbox full of spam? Here are four ways spammers get your email address, and how you can protect your email address from spammers in the future.

There are four main ways spammers get your email address. Here’s a look at each method and what you can do to protect your inbox from these unwanted intruders.

Spammers buy email addresses both legally and illegally. When you create an account on a website or service or make an online purchase, read the privacy policy carefully. Your email address could be sold to a marketing list, creating unwanted junk mail. In addition, dishonest ISP employees sometimes sell email lists on eBay or the black market.

Any text on a web page that contains the @ sign is fair game for email harvesting programs. Spammers and hackers use complex automated tools to scan the web and collect email addresses. Spammers harvest email addresses from mailing lists, websites, chat rooms, domain contacts, and more. Understand that if you post your email address online, a spammer will find it.