Email, Messaging, & Video Calls Email Underlining in a Plain Text Email It's not as pretty as HTML, but it's easy by Heinz Tschabitscher Writer A former freelance contributor who has reviewed hundreds of email programs and services since 1997. our editorial process Heinz Tschabitscher Updated on June 25, 2019 Ulf Wittrock/EyeEm/Getty Images Email Yahoo! Mail Gmail Tweet Share Email Most emails use HTML formatting where the text is encoded to handle bold, italics, colors, positioning, layout, and other font formats. In contrast, a plain text email looks like it was typed on a typewriter. Plain text does not allow font formatting, images, and hyperlinks. Pictures that display in the text cannot be inserted in the messages, although images can be included as attachments. Plain text often displays in a mono-spaced font in which each character takes up the same amount of space on the line as every other character. Why Use Plain Text Emails? Sometimes, it's more appropriate to send a plain text email than to send an HTML message. Use plain text when you're not sure if the recipient's email app will render HTML correctly. While plain text emails are not as attractive as HTML-based emails, plain text emails play a significant role in a well-rounded email marketing strategy. Plain text email generally has a higher open and click rate than HTML email. While the plain text may be plain, it's universally readable by devices that receive emails, from phones and tablets to computers of all platforms. HTML, Plain Text, and MIME Most emails are sent via SMTP in MIME (multipurpose internet mail extensions) format, which means that a plain text version of the email message is bundled along with the HTML version. Unless you send out solely plain text email, multipart MIME should be part of every email campaign because spam filters don't mark the plain text alternative as junk mail, and some people prefer it as well. How to Mimic Underlining in Plain Text Email Messages When you want to add formatting elements for emphasis, such as underlining, mimic an underline effect while retaining the reliable legibility you're after. To indicate underlining in a plain text email, use underscore characters at the beginning and end of the underlined passage, for example: _example text_ You can mimic boldface and italics in a similar manner. Use asterisks at the beginning and end of the words you want to mimic as bold, for example: *this text* Put a slash at the beginning and end of a phrase you want to mimic as italics: /like this/ Although you can't create true underlined, boldfaced, or italicized text in a plain text email, these three methods are acceptable, widely understood ways of adding emphasis without the use of HTML. So, What Is Rich Text? Rich Text (RTF) falls between HTML and plain text as far as formatting capabilities go. With rich text, you can do basic formatting such as font choice, font size, color, and styles that include italics, bold, and underlining. Rich text also supports text alignment, so you can center a line of text in your email if you want to. However, you can't add links, in-line graphics or videos like you can with HTML. By default, when you use rich text in an email, most email providers convert the RTF-formatted messages to HTML.