Instead of using the IE-based HTML rendering engine, Outlook 2007/2010 use the MS Word HTML rendering engine.
Following things won’t work in Outlook 2007/2010:
- No background images in DIV tags and TABLE cells.
- No nested background colors. A background color in a DIV or TABLE cell displays fine. However, if you nest another TABLE or DIV within the element, the background color vanishes.
- No FLOAT or POSITION attribute in DIV tags. In other words, CSS-based layouts won’t work in Outlook 2007. (As far as possible, avoid DIV tags in your html; use TABLE instead)
- No animated .gif files or Flash content. Animated .gif files just won’t animate. With Flash, you’ll just get a big red X.
- Text alignment will be justified to the left
- Text will have double spacing
- Forms will not work in the emails sent to Outlook 2007 and Outlook 2010
Email clients consider email forms to be a security risk. While some email clients simply warn you of potential danger, others like Outlook 2007 outright disable the forms. Given the sporadic support for forms in emails, we recommend linking to a form on a website rather than embedding it in the email.