When it comes to coding your HTML email, there are some common things to avoid. These things are often ignored by email clients, which means that your email may not display the way you want it to.
Avoid any of the following:
Web forms embedded within your email will not render/ function properly in most email clients.
If you want to use an image map, the best thing to do is slice your image and then put it back together using tables. You can then link each of the images. When using an image map, some features like heat maps in reporting may not function as expected.
Flash & Animated GIF Images
Outlook 07/2010 doesn’t support Flash. If you do choose to use a flash file or animated GIF, only the last frame will be displayed as a static image.
CSS Positioning or Float Styles
These will be largely ignored by most email clients.
Any Programming Code
Will be stripped before the email reaches the recipients inbox.
The only email client this will work in is Apple Mail. If you want to simulate embedding a video, you can take a screenshot of the play screen, insert the screenshot as an image in your email, and then link this image to your video hosted online.