Email that is formatted using Hypertext Markup Language, as opposed to plain text email.
HTML email brings some of the visual artistry of the Web to the email inbox, previously characterized by plain text. As email inboxes become increasingly cluttered, HTML email provides one way to stand out from the crowd. Some of the available elements include graphics, formatted text and background colors. Used properly, HTML email has the potential to communicate more information, which can lead to higher response rates. As with Web pages, however, load time is still an issue.
Privacy and security watchdogs have claimed that there are risks associated with using HTML email, such as the ability to embed cookies and scripts in messages. Surfing the Web carries these same risks, but you decide which sites you want to visit on the Web. With email, you may be visited by anonymous spammers with questionable intentions.
see also: Email Marketing Tools