HTML versus Text discussion leads to the subject regarding the contents of HTML formatted emails. Since HTML can include any number or combination of rich content features such as static images and flash images, it is essential to understand the advantages and disadvantages of using images in the email messages. Too many images may distract the users and result in invisible email contents due to the blocking of images by email providers (such as MSN Hotmail, Google, Yahoo, and AOL) and software such as Microsoft Outlook.