3 Message Formats in Outlook and When to Use Which

Understanding Outlook email formats

3 Message Formats in Outlook and When to Use Which

Using a message format that your recipient's application supports ensures messages can be opened and read. Microsoft Outlook has three different message formats that you can use for different situations.

Information in this article applies to Outlook 2019, 2016, 2013, 2010; Outlook for Office 365, Outlook Online, and Outlook for Mac.

Three Message Formats in Outlook and When to Use Which

Each message format has different options, the one that you choose determines whether you can add formatted text, such as bold fonts and bullets, and whether you can add pictures to the message body.

What's essential is choosing a format that the recipient will be able to see, as some e-mail applications don't support formatted messages or pictures.

With Outlook, you can send messages in three different formats.

Plain Text

Plain Text sends emails that contain 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 is beneficial if you do not depend on any fancy formatting, and it ensures maximum compatibility. All email applications support plain text and every email account will be able to read your message.


HTML send emails that contain HTML formatting. This is the default message format in Outlook. It is also the best format to use when you want to create messages that are similar to traditional documents, with various fonts, colors, and bullet lists. You can even include pictures that display inline and use other formatting tools.

Most people can receive HTML-formatted messages (although some prefer plain text). By default, when you select either of the options that allow formatting (HTML or Rich Text), the message is sent in HTML format. So when you use HTML, you know that what you send is what the recipient will see.

Rich Text Format (RTF)

Rich Text is Outlook's proprietary message format. RTF supports text formatting, including bullets, alignment, and linked objects.

Outlook automatically converts RTF formatted messages to HTML when you send them to an internet recipient so that the message formatting is maintained and attachments are received. Outlook also automatically formats meeting and task requests and messages with voting buttons so that these items can be sent intact across the internet to other Outlook users, regardless of the default format of the message.

If the internet-bound message is a task or meeting request, you must use RTF. Outlook automatically converts it to Internet Calendar format, a common format for internet calendar items, so that other e-mail applications can support it. 

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. Set the default format in Outlook.