Email was invented four decades ago and it is still the most popular communication technologies. A Reuter’s poll conducted in 2012 showed that nearly 85% of people around the world use email to stay connected as compared to 62% that connect on social media. Nowadays, more than 71% of marketers use email as a medium to connect with customers and email marketing tools make it easy to set up a newsletter campaign. Marketers must understand why spam filters behave the way they do & is crucial in strategizing email marketing techniques. To know more about email marketing techniques, follow:  http://it.toolbox.com/blogs/it-small-business/understanding-the-technology-behind-email-marketing-69797