When people click, they're sent to the spammers' phishing or malware websites -- where they're tricked into providing personal information, activating a virus or downloading malicious software.

• Spammers collect email addresses from chatrooms, websites, customer lists, newsgroups and email viruses, which harvest users' address books. These addresses are then sold to other spammers. 
  
  
• They use "email appending" or "epending" to gather additional data about their targets. They start with what they know -- like a postal address -- and use it to find the person's email address. 
  
  
• Much spam is sent to invalid email addresses. 
  
  
• Spam makes up the majority of all email sent.

How to report spam to CenturyLink