How to embed an Image Stream to MailMessage

Question

I'm having some difficulty embedding an image from the Properties.Resources to a MailMessage, currently the image does not show in the email i receive.

I have successfully embedded the image from a directory location but would prefer if the image came from memory/the application.

Here is a simplified version of what I am doing.

 Bitmap b = new Bitmap(Properties.Resources.companyLogo);
 MemoryStream logo = new MemoryStream();
 b.Save(logo, ImageFormat.Jpeg);



 MailMessage newEmail = new MailMessage(from, to);
 newEmail.Subject = subject;
 newEmail.IsBodyHtml = true;

 LinkedResource footerImg = new LinkedResource(logo, "image/jpeg");
 footerImg.ContentId = "companyLogo";
 AlternateView foot= AlternateView.CreateAlternateViewFromString(body + "<p> <img src=cid:companyLogo /> </p>", null, "text/html");

 foot.LinkedResources.Add(footerImg);

 newEmail.AlternateViews.Add(foot);             

 SmtpClient server = new SmtpClient(host, port);
 server.Send(newEmail);

Futtock

where does "head" come from, and what do you do with "foot"? – Steffens

that is irrelevant(but i made a rename mistake when copying out the source), either way i've solved the problem - Short answer is don't use Bitmap.Save instead convert the image to a Byte[] and instantiate the MemoryStream with it. I will post the full answer later. – Futtock

Answer 1

Ok i have solved the problem.

Instead of using the BitMap save method I converted the BitMap to Byte[] and gave the memory stream the Byte[]

Did not work :

 b.Save(logo, ImageFormat.Jpeg);

Did Work:

Bitmap b = new Bitmap(Properties.Resources.companyLogo);
ImageConverter ic = new ImageConverter();
Byte [] ba = (Byte[]) ic.ConvertTo(b,typeof(Byte[]));
MemoryStream logo = new MemoryStream(ba);

I think it has something to do with the Bitmap.Save method, in the MSDN lib it mentioned that the stream has to have an offset of 0.

Futtock

Just tell us, bro, how did you discover this approach? +1 – Rutter

Answer 2

Bitmap b = new Bitmap(Properties.Resources.companyLogo);
MemoryStream logo = new MemoryStream();
b.Save(logo, ImageFormat.Jpeg);

After you do the save, you have to "seek" the MemoryStream back to the start.

logo.Position = 0;

Adrianneadriano

I wanted to use this approach and couldn't get it to work. Attachment was always 0 sized. Setting the position to 0 did the trick! @Adrianneadriano Thanks so much :-) – Guarded

Answer 3

You can embed the image and skip working with resources by converting it to base64 instead:

public static string BitmapToBase64(Bitmap b)
{
   ImageConverter ic = new ImageConverter();
   byte[] ba = (byte[])ic.ConvertTo(b, typeof(byte[]));
   return Convert.ToBase64String(ba, 0, ba.Length);
}

and use it as html image src :

string logoimage="<img src='data:image/png;base64," + BitmapToBase64(logo) + "'>";

Note that converting to Base64 slighly increases the size of the image.

Kandis

Unfortunately some webmail clients don't work too well with base64 embedded images. See https://mcmap.net/q/176516/-base64-images-to-gmail – Populous

Answer 4

Try look here:

http://www.eggheadcafe.com/community/aspnet/2/10219822/send-mail-with-atttached-image.aspx

From the link above:

static void EmbedImages()
{
   var mail = new MailMessage();

   mail.From = new MailAddress("[email protected]");
   mail.To.Add("[email protected]");
   mail.Subject = "This is an email";

   var plainView = AlternateView.CreateAlternateViewFromString(
      "This is my plain text content, viewable by those clients that don't support html",
      null, "text/plain");

   var htmlView = AlternateView.CreateAlternateViewFromString(
      "Here is an embedded image.<img src=cid:companylogo>", 
      null, "text/html");

   LinkedResource logo = new LinkedResource( "c:\\temp\\logo.gif" );
   logo.ContentId = "companylogo";

   htmlView.LinkedResources.Add(logo);

   mail.AlternateViews.Add(plainView);
   mail.AlternateViews.Add(htmlView);

   var smtp = new SmtpClient("127.0.0.1"); //specify the mail server address
   smtp.Send(mail);
}

Holmen

I know that works - adding the image from a location - but i would like to use the Application's resources. The LinkedResource has an overload to take a Stream instead of the file location. I tried to use that but either the initial image -> stream is not working or the embedding of the image's stream -> LinkedResource – Futtock

He asked about to use Bitmap and MemoryStream and not the direct image file... – Rutter

Watch out - MailMessage and SmtpClient implement IDisposable so should be in a using statement or disposed manually. – Unorganized

This isn't related the the OPs question. – Cyr

If I add both views, html and plain, then when receiving emails it always shows in plain mode. If I add only html then it always shows html. Is there a way to prioritize this, so it first tries to load html view if something goes wrong then it loads the plain? – Workmanlike

Answer 5

Instead of adding the "logo" to Resources, I added it directly to the project and set it to build as an "Embedded Resource".

Then using System.Reflection.Assymbly I can get it (I assume directly) as a Stream:

  var _assembly = Assembly.GetExecutingAssembly();
  var _logoStream = _assembly.GetManifestResourceStream("[Project].[Filename].png");
  var logo = new LinkedResource(_logoStream, "image/png");
  logo.ContentId = "Logo";
  html.LinkedResources.Add(logo);

Gand

Answer 6

Here's how I implemented it:

var htmlBody = "...<img src=\"cid:logo.jpg\" />...";
    
var message = new MailMessage();
message.To.AddRange(mailAddresses);
message.From = fromAddress;

var plaintextView = AlternateView.CreateAlternateViewFromString(plaintextBody, new ContentType(MediaTypeNames.Text.Plain));
plaintextView.ContentType.CharSet = Encoding.UTF8.WebName;
message.AlternateViews.Add(plaintextView);
    
var logoLinkedResource = new LinkedResource(new MemoryStream(Properties.Resources.Logo), MediaTypeNames.Image.Jpeg)
{
    ContentId = "logo.jpg",
    TransferEncoding = TransferEncoding.Base64
};
    
var htmlView = AlternateView.CreateAlternateViewFromString(htmlBody, new ContentType(MediaTypeNames.Text.Html));
htmlView.ContentType.CharSet = Encoding.UTF8.WebName;
htmlView.LinkedResources.Add(logoLinkedResource);
message.AlternateViews.Add(htmlView);
    
message.Subject = subject;

This is fairly similar to some of the above answers, but a little different, and took me a while to get the details right for my case.

Note that email clients will use the last supported part/alternative view, so the text version should always be added first.

Carter