In my app, I am composing an HMTL email message with the 3.0+ MFMailComposeViewController.
To do this, I created an HTML file, with some placeholders.
In my cod
I don't know if the HTML format is a must have for you, but actually embedding an image in an email can be achieved without using HTML, just with image as attachment.
Just have a look at the way it is achieved here :
http://iphone-dev-tips.alterplay.com/2009/11/attaching-image-of-uiview-to-email.html
the crucial part is this :
// ATTACHING A SCREENSHOT
NSData *myData = UIImagePNGRepresentation(screenshot);
[controller addAttachmentData:myData mimeType:@"image/png" fileName:@"route"];
You get the PNG representation of your UIImage (as NSData) and you attach it yo your email.