Outlook 2007 - animated GIF

As per Microsoft:

Other Unsupported Web-Related Features
The following is a list of all other Web-related features that Word 2007 does not support:

• Animated GIF images. Only a static representation of the GIF image shows.
• Flash. Only a red “X” shows in the area where the flash would display.

Steps to view the animation:
1. Double click the message in Outlook 2007 to open it in its own
Window.
2. On the “Message” toolbar, in the 2nd section, there is an “Other
Actions” button.
3. In the “Other Actions” drop-down menu, select “View in Browser”.