Disclaimer with Logo

Hi,

I've added the disclaimer through the built in transport rules in Exchange and followed the method from Microsoft website to add a logo via HTML Img tag but it is not working for me. when I send an e-mail the html tag doesn't show and instead of an image I just get my webserver address within brackets. if I copy paste the link in another page I can get the image and view it fine. Am I missing a step?

This is the transport rule:

<IMG src="http://server.mydomain.ca/img/logo.gif">

Then the disclaimer

This is the response I get

[http://server.mydomain.ca/img/logo.gif]