You have to add the images as an attachment. The rendered email that you see with HTML doesn't get rendered properly with the missing image URL.
here is an example: the caveat is that if you want to include things like a PDF you must include an image otherwise mfmailcomposer will fail... this in an apple bug.
I found the solution... Isubmitted a bug on Apple radar about it. MFMailcomposer has a bug in which you have to send an image along with your extra attachments in order to get the weird items like a pdf to work... try this and replace the pdf with your card:
MFMailComposeViewController *controller = [[MFMailComposeViewController alloc] init];
NSString *emailSubject = [NSString localizedStringWithFormat:@"MedicalProfile"];
[controller setSubject:emailSubject];
NSString *fileName = [NSString stringWithFormat:@"%@.pdf", profileName];
NSString *saveDirectory = NSTemporaryDirectory();
NSString *saveFileName = fileName;
NSString *documentPath = [saveDirectory stringByAppendingPathComponent:saveFileName];
*** YOU MUST INCLUDE AN IMAGE OR THE PDF ATTATCHMENT WILL FAIL!!!***
// Attach a PDF file to the email
NSData *pdfData = [NSData dataWithContentsOfFile:documentPath];
[controller addAttachmentData:pdfData mimeType:@"application/pdf" fileName:fileName];
// Attach an image to the email
NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"miniDoc" ofType:@"png"];
NSData *imageData = [NSData dataWithContentsOfFile:imagePath];
[controller addAttachmentData:imageData mimeType:@"image/png" fileName:@"doctor"];
[controller setMessageBody:[NSString stringWithFormat:@"%@'s Medical Profile attatched!", profileName] isHTML:NO];
[self presentModalViewController:controller animated:YES];
controller.mailComposeDelegate = self;
[controller release];