Microsoft Outlook does not support all styles from email campaigns. Here is a consolidated list of what styles Outlook supports for what HTML tags. Although the article references Outlook 2007, it applies to Outlook 2010 as well.
All HTML elements and and their Outlook support level can be found here.
Note
Paragraph, body, and div tags only support Core Extended CSS values. All post text is wrapped in paragraph tags. This means all styles under Full Support will not display on paragraph tags in Outlook.
Image floats (float: left; float: right; etc) are unsupported.
Unsupported CSS styles
The following CSS styles are unsupported:
- background-attachment
- background-image
- background-position
- background-repeat
- clear
- display
- float
- list-style-image
- list-style-position
- text-transform
- word-spacing
Supported HTML tag styles
HTML tags that receive Core support from Outlook can be given the following styles:
- color
- font
- font-family
- font-style
- font-variant
- font-size
- font-weight
- text-decoration
- background (only color)
- background-color
- text-align
- vertical-align
- letter-spacing
- line-height
- white-space
- display
- border
- border-color
- border-style
- border-width
- src
- size
- marks
- page-break-before
- page-break-after
- page-break-inside
- list-style
- list-style-type
- unicode-bidi
- border-collapse
HTML tags with Core Extended support
HTML tags that receive Core Extended support, support all of the core styles along with the following:
- text-indent
- margin
- margin-left
- margin-right
- margin-top
- margin-bottom
If an HTML element does not receive Full support, the following styles will not display:
- width
- height
- padding
- padding-left
- padding-right
- padding-top
- padding-bottom
- border-left
- border-right
- border-top
- border-bottom
- border-left-color
- border-left-width
- border-left-style
- border-right-color
- border-right-width
- border-right-style
- border-top-color
- border-top-width
- border-top-style
- border-bottom-color
- border-bottom-width
- border-bottom-style