如果您使用的是.NET 2或更高版本,则可以使用AlternateView和LinkedResource类,如下所示:
string html = @"<html><body><img src=""cid:YourPictureId""></body></html>";
AlternateView altView = AlternateView.CreateAlternateViewFromString(html, null, MediaTypeNames.Text.Html);
LinkedResource yourPictureRes = new LinkedResource("yourPicture.jpg", MediaTypeNames.Image.Jpeg);
yourPictureRes.ContentId = "YourPictureId";
altView.LinkedResources.Add(yourPictureRes);
MailMessage mail = new MailMessage();
mail.AlternateViews.Add(altView);
希望您可以推断出VB等效项。