在邮件正文VB.NET中发送包含图像的HTML电子邮件

Question

I am working on a Mail App in VB.NET. The mail app sends mail in two steps :

1.It converts the Email body(rtf) to HTML

2.Then it sends the converted HTML as the email body

For these, i am using EASendMail(to send email),Itenso RTF2HTML converter(to convert RTF to HTML) . Now my email body is basically a RichTextBox(bodytxt.text).The code used are :

  Imports Itenso.Rtf.Converter.Html
  Imports EASendMail
  Imports Itenso.Rtf.Support
  Imports Itenso.Rtf

   Dim rr As String = bodytxt.Rtf.Replace("\0", "")
   Dim rtfDocument As IRtfDocument = RtfInterpreterTool.BuildDoc(rr)
   Dim htmlConverter As New RtfHtmlConverter(rtfDocument)
   Dim html1 As String = htmlConverter.Convert()

    Dim oMail As New SmtpMail("TryIt")
            Dim oSmtp As New EASendMail.SmtpClient()
            oMail.From = fromtxt.Text
            oMail.To = New AddressCollection(totxt.Text)
            oMail.Subject = subjecttxt.Text
            oMail.HtmlBody = html1
            Dim oServer As New SmtpServer(MailConfig.host.Text)
            oServer.Port = MailConfig.port.Text
            oServer.ConnectType = SmtpConnectType.ConnectSSLAuto
            oServer.User = fromtxt.Text
            oServer.Password = MailConfig.password.Text
            Dim r As Integer
            If ListBox1.Items.Count <= 0 Then
            Else
                oMail.AddAttachment(ListBox1.Items(r))
            End If
            oSmtp.LogFileName = Application.StartupPath & "\maillog.OFPTX"

            oSmtp.SendMail(oServer, oMail)

Now this code works fine and sends the email as HTML-maintaining all text formatting . The problem is, suppose i add an image in the rich textbox, then the image is sent but it can't be opened/viewed from my mail client's inbox.In Gmail, It shows as a broken image and "Open image in new tab" show "We can't display this image"...

1.What am i doing wrong ?How to send the image not as an attachment but a part of the email body ?

2.Can my code be improved ?

Answer 1

Ok so I've dealt with this issue many times. When you drag an image into the rich text box, it may just kind of "live there" in memory.

What is the markup look like in the rich text box? Typically there are 2 ways I've tackled this with web applications that involve rich text boxes (or any application) where you can drag an image in:

1. When the image is drag and dropped into the richtextbox, save it to the server, or a file server - and serve up a link. Now you can add an tag in your email's html In my vb.net project, it's an asp web project, so I'm utilizing a web service, however the RichTextBox.Rtf property may work - see if the RTF file contains the image in it: https://msdn.microsoft.com/en-us/library/system.windows.forms.richtextbox.rtf(v=vs.110).aspx
2. Convert the image to a data URI: https://www.abeautifulsite.net/convert-an-image-to-a-data-uri-with-your-browser