Software & Apps MS Office 51 51 people found this article helpful 3 Message Formats in Outlook and When to Use Which Understanding Outlook email formats 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 February 17, 2020 Outlook Mail. MS Office Outlook Word Excel Powerpoint Tweet Share Email Microsoft Outlook offers three different message formats: plain text, HTML, and rich text (RTF). The primary differences among these message formats concern how they handle images, characters such as bullets, and styles such as bolding. Information in this article applies to Outlook 2019, 2016, 2013, 2010; Outlook for Microsoft 365, Outlook Online, and Outlook for Mac. Choosing the Right Format The goal of any form of communication is for your message to be understood clearly. For that to happen, your recipient must be able to see it. HTML: An email in HTML format shows all the colors, positioning, fonts, styles, etc. you used to create it—provided that your recipient has set Outlook to receive emails in HTML format. Most users do; in fact, that's the default setting. Plain text: An email sent in plain text format contains only text characters. Plain text doesn't support bold, italic, colored fonts, or other text formats. It also doesn't support pictures that are displayed directly in the message body, although you can include pictures as attachments. This format ensures maximum compatibility; all email applications support plain text, and every email account will be able to read your message. RTF: Rich text formatting (RTF), Outlook's proprietary message format, is somewhat of a middle ground. It supports text formatting, including bullets, alignment, and linked objects. You can use it when sending to other Outlook and Exchange users, but Microsoft recommends sending in HTML regardless. How to Set the Default Format If you want to send all messages in a specified format, don't change the formatting for an individual message. Instead, change the default format.