HTML Email Stationery

[George]

Is it possible to implement personalized stationery for Web-based (HTML)
email that expands vertically to accommodate various length messages?

Some services exist for this purpose but they are limited to using
Outlook and Outlook Express email clients, like the service at:

http://www.stationerycentral.com/cuteeditor/Blended-EPT-SC-TryIt-Site-KLS.html

What I'm looking for should be possible because the above is an example that
works with Webmail. However, it is not sold that way; it's just a demo.

Please go easy on me - I'm no HTML expert ... )