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Glossary · Message format

HTML email

An email whose body is written in HTML (text/html), allowing layout, styling, images and links, rendered by each mail program with its own limited HTML and CSS support.

What it means

HTML email is a text/html MIME part, usually paired with a plain-text alternative. Mail programs are not browsers: support for HTML and CSS varies widely from one program to the next, and Can I email documents feature support across clients, which is why email HTML still leans on tables and inline styles.

HTML is also part of what filters read. Google asks for HTML formatted to HTML standards, warns against hiding content with HTML and CSS, and asks for links whose destination is clear. Size matters as well: Gmail clips long HTML.

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