Recently, I have found an issue with RichTextBox. I create a RadDocument with an inserted image on it and then convert in into html using Telerik.Windows.Documents.FormatProviders.Html.HtmlFormatProvider. I can see the image if I open the file with any browser. However, if I email that html document as a body of email then my gmail doesn't show it as image. It shows it as text like <image and etc>. I believe it happens because of security issues. Has anybody ever had the same problem? Maybe there are some settings for gmail to show the image?