The content of the email provides the communication or message. Email receivers have cracked down on malicious communication from spammers, such as phishing, malware and virus distribution, or scams, by implementing robust content filters. These content filters perform automated reviews of email content to look for unwanted email. Technically savvy users rely on open source content filters like the Apache Spam Assassin. Enterprises are more likely to rely on content filters like Google’s Postini or Symantec’s BrightMail. 

If the receiver’s content filter has determined that your content has spam-like characteristics, your content will likely get flagged and diverted from a recipient’s inbox. You can find some suggestions about how to avoid having your email content caught in filters, below.