Send inline image in email

Solution 1:

Some minimal c# code to embed an image, can be:

MailMessage mailWithImg = GetMailWithImg();
MySMTPClient.Send(mailWithImg); //* Set up your SMTPClient before!

private MailMessage GetMailWithImg() {
    MailMessage mail = new MailMessage();
    mail.IsBodyHtml = true;
    mail.AlternateViews.Add(GetEmbeddedImage("c:/image.png"));
    mail.From = new MailAddress("yourAddress@yourDomain");
    mail.To.Add("recipient@hisDomain");
    mail.Subject = "yourSubject";
    return mail;
}

private AlternateView GetEmbeddedImage(String filePath) {
    LinkedResource res = new LinkedResource(filePath);
    res.ContentId = Guid.NewGuid().ToString();
    string htmlBody = @"<img src='cid:" + res.ContentId + @"'/>";
    AlternateView alternateView = AlternateView.CreateAlternateViewFromString(htmlBody, null, MediaTypeNames.Text.Html);
    alternateView.LinkedResources.Add(res);
    return alternateView;
}

Solution 2:

Try this

 string htmlBody = "<html><body><h1>Picture</h1><br><img src=\"cid:filename\"></body></html>";
 AlternateView avHtml = AlternateView.CreateAlternateViewFromString
    (htmlBody, null, MediaTypeNames.Text.Html);

 LinkedResource inline = new LinkedResource("filename.jpg", MediaTypeNames.Image.Jpeg);
 inline.ContentId = Guid.NewGuid().ToString();
 avHtml.LinkedResources.Add(inline);

 MailMessage mail = new MailMessage();
 mail.AlternateViews.Add(avHtml);

 Attachment att = new Attachment(filePath);
 att.ContentDisposition.Inline = true;

 mail.From = from_email;
 mail.To.Add(data.email);
 mail.Subject = "Client: " + data.client_id + " Has Sent You A Screenshot";
 mail.Body = String.Format(
            "<h3>Client: " + data.client_id + " Has Sent You A Screenshot</h3>" +
            @"<img src=""cid:{0}"" />", att.ContentId);

 mail.IsBodyHtml = true;
 mail.Attachments.Add(att);

Solution 3:

    protected void Page_Load(object sender, EventArgs e)
    {
        string Themessage = @"<html>
                          <body>
                            <table width=""100%"">
                            <tr>
                                <td style=""font-style:arial; color:maroon; font-weight:bold"">
                               Hi! <br>
                                <img src=cid:myImageID>
                                </td>
                            </tr>
                            </table>
                            </body>
                            </html>";
        sendHtmlEmail("[email protected]", "tomailaccount", Themessage, "Scoutfoto", "Test HTML Email", "smtp.gmail.com", 25);
    }

    protected void sendHtmlEmail(string from_Email, string to_Email, string body, string           from_Name, string Subject, string SMTP_IP, Int32 SMTP_Server_Port)
    {
        //create an instance of new mail message
        MailMessage mail = new MailMessage();

        //set the HTML format to true
        mail.IsBodyHtml = true;

        //create Alrternative HTML view
        AlternateView htmlView = AlternateView.CreateAlternateViewFromString(body, null, "text/html");

        //Add Image
        LinkedResource theEmailImage = new LinkedResource("E:\\IMG_3332.jpg");
        theEmailImage.ContentId = "myImageID";

        //Add the Image to the Alternate view
        htmlView.LinkedResources.Add(theEmailImage);

        //Add view to the Email Message
        mail.AlternateViews.Add(htmlView);

        //set the "from email" address and specify a friendly 'from' name
        mail.From = new MailAddress(from_Email, from_Name);

        //set the "to" email address
        mail.To.Add(to_Email);

        //set the Email subject
        mail.Subject = Subject;

        //set the SMTP info
        System.Net.NetworkCredential cred = new System.Net.NetworkCredential("[email protected]", "fromEmail password");
        SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587);
        smtp.EnableSsl = true;
        smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
        smtp.UseDefaultCredentials = false;
        smtp.Credentials = cred;
        //send the email
        smtp.Send(mail);
    }

Solution 4:

In addition to the comments above, I have the following additional comments:

Do not mix Attachments and AlternativeView, use one or the other. If you mix them, the inline attachments will be rendered as unknown downloads.
While Outlook and Google allow standard HTML-style "cid:att-001" this does NOT work on iPhone (late 2016 patch level), rather use pure alpha numeric "cid:att-001" -> "cid:att001"

As an aside: Outlook (even Office 2015) rendering (still the clear majority for business users) requires the use of TABLE TR TD style HTML, as it does not fully support the HTML box model.

Solution 5:

An even more minimalistic example:

var linkedResource = new LinkedResource(@"C:\Image.jpg", MediaTypeNames.Image.Jpeg);

// My mail provider would not accept an email with only an image, adding hello so that the content looks less suspicious.
var htmlBody = $"hello<img src=\"cid:{linkedResource.ContentId}\"/>";
var alternateView = AlternateView.CreateAlternateViewFromString(htmlBody, null, MediaTypeNames.Text.Html);
alternateView.LinkedResources.Add(linkedResource);

var mailMessage = new MailMessage
{
    From = new MailAddress("[email protected]"),
    To = { "[email protected]" },
    Subject = "yourSubject",
    AlternateViews = { alternateView }
};

var smtpClient = new SmtpClient();
smtpClient.Send(mailMessage);