MHTML

Topic Last Modified: 2006-06-12

MIME Encapsulation of Aggregate HTML Documents (MHTML) is an Internet standard that defines the Multipurpose Internet Mail Extensions (MIME) structure used to send HTML content in message bodies along with those resources referenced from within the HTML. The HyperText Markup Language (HTML) is a markup language used to create documents that are portable between various platforms. One of its key features is the ability to render a document composed of separate resources, such as images, sound files, cascading style sheets, and Microsoft® ActiveX® objects, inline with the marked up text. Many e-mail clients, such as Microsoft Outlook® Express, are capable of displaying HTML pages just as they would appear in a Web browser. As e-mail content, such HTML documents usually include links to other resources that are available on the network. The HTML author identifies these resources for inclusion in the page by using relative or absolute URLs as attributes within HTML markup elements.

In many cases, it is desirable to include external resources referenced by the HTML document in the message body itself. The MHTML specification provides the architecture used to encapsulate referenced resources within the message body. This allows the e-mail client to construct and render the page without retrieving these resources directly over the network.