Insert inline image in email (body format RTF)

Hello.

I would like to create transport agent which insert a picture in email with event OnRoutedMessage.

I followed this post:http://blogs.technet.com/b/postwoman/archive/2010/09/14/step-by-step-how-to-create-a-routing-agent.aspx

Now I also want to insert an image when the mail format is RTF.
I used the classes (RtfToHtml and HTMLtoRTF) and I get an email with a good image inserted. However, this picture is not displayed correctly.

http://social.technet.microsoft.com/Forums/getfile/173352

Do you have any ideas?