如何使用Oracle的UTL_SMTP发送包含嵌入图像的消息体?

I'm attempting to use Oracle's 11.g's UTL_SMTP to send a message body that includes an embedded image. I have this process working for a standard text body, and for an eMail that may contain attachments (Word doc, JPG image, etc.). I'm stuck on making this work with an image embedded in the body of the eMail. When I include and embedded image, the eMail displays in Outlook 2013 as a red X where the image should be. The rest of the text appears fine. The html body of the eMail is passed in to the procedure via "p_html".I'm attempting to use Oracle's 11.g's UTL_SMTP