How to Change the Default Email Format in Outlook: HTML vs Plain Text vs Rich Text

You may need to change Outlook’s default email format for consistency or compatibility. Outlook can send messages in HTML, Plain Text, or Rich Text format, each with different capabilities. This article explains the differences between these formats and provides the steps to set your preferred one as the default for all new messages.

Understanding Outlook’s Three Email Formats

Before changing the default, you should know what each format offers. Your choice affects how your email appears to recipients and what features you can use.

HTML Format

HTML is the default and most common format in Outlook. It allows for rich formatting including multiple fonts, font sizes, colors, bulleted lists, embedded pictures, and clickable hyperlinks. Most modern email clients display HTML messages correctly, providing a professional and visually engaging experience.

Plain Text Format

Plain Text format contains only unformatted text. It does not support different fonts, colors, images, or hyperlinks. All text appears in a single font, typically the recipient’s default email font. This format is universally compatible with every email system and is often used for formal communication or when sending to mailing lists where HTML might be stripped.

Rich Text Format

Rich Text Format is a Microsoft-specific format that supports basic formatting like bold, italics, and underlining. It also supports some Outlook-specific features like Task Requests and Voting Buttons. However, RTF is not widely supported outside of Microsoft email environments like Exchange Server. Recipients using other email services may receive a Plain Text version or an attachment instead.

Steps to Set the Default Email Format

You can set a global default that applies to all new messages, replies, and forwards. The setting is located in the main Outlook options.

1. Open Outlook Options
   Click the File tab in the top-left corner of the Outlook window. Then select Options from the left-hand menu.
2. Navigate to Mail Settings
   In the Outlook Options window, click the Mail category on the left sidebar.
3. Find the Compose Messages Section
   Scroll down within the Mail options until you see the section titled “Compose messages”.
4. Select Your Default Format
   Click the dropdown menu next to “Compose messages in this format:”. Choose HTML, Plain Text, or Rich Text from the list.
5. Save the Change
   Click the OK button at the bottom of the Outlook Options window to save your new default setting and close the window.

Changing the Format for a Single Message

You can override the default format for an individual email while you are composing it. This is useful for sending one message in Plain Text for compatibility.

1. Start a New Email
   Click New Email on the Home tab to open a new message window.
2. Access the Format Text Tab
   In the new message window, click the Format Text tab on the ribbon. This tab contains formatting controls.
3. Choose a Format
   In the Format group on the far left, you will see three buttons: HTML, Plain Text, and Rich Text. Click the button for your desired format. The message window will update immediately.

Common Mistakes and Formatting Issues

Changing formats can sometimes lead to unexpected results. Be aware of these common situations.

Pasting Formatted Text Loses Formatting

If you copy text from a website or Word document and paste it into a Plain Text email, all formatting will be removed. To keep formatting, ensure your message is set to HTML or Rich Text format before pasting. Use the Paste Special command on the Message tab for more control.

Recipients See a Winmail.dat Attachment

This occurs when you send a message in Rich Text Format to an email system that does not support it, like Gmail or Yahoo Mail. The recipient receives an unreadable file named winmail.dat. To avoid this, do not use Rich Text Format when emailing outside your organization unless you are certain the recipient uses Outlook or Exchange.

Hyperlinks Are Not Clickable

In Plain Text format, web addresses and email addresses are just text. Recipients cannot click them to open a browser. If your message requires clickable links, you must use HTML or Rich Text format.

HTML vs Plain Text vs Rich Text: Key Differences

Item	HTML Format	Plain Text Format	Rich Text Format (RTF)
Best For	Standard business emails, newsletters, marketing	Mailing lists, high compatibility, formal text-only communication	Internal Exchange/Outlook communication using features like voting buttons
Formatting Support	Full support: fonts, colors, images, hyperlinks, tables	No formatting support	Basic text formatting and some Outlook-specific features
External Compatibility	High, supported by all major web and desktop clients	Universal, supported by every email system	Very low, often causes winmail.dat attachment for non-Outlook users
File Size	Larger due to formatting code	Smallest	Moderate
Default in Outlook	Yes	No	No

You can now control how your emails are formatted by default and for individual messages. For most users, HTML remains the best choice for daily use. If you frequently switch formats, add the Format button to your Quick Access Toolbar for one-click changes. Use the keyboard shortcut Ctrl+Shift+S while composing a message to quickly cycle through the available formats.