将一封电子邮件作为附件附加到另一封电子邮件上

Question

我想知道如何在C#中将电子邮件作为附件附加到另一个电子邮件上。

细节：

1. I am writing a plugin for outlook
2. I am getting the error on this line : Attachment attach = new Attachment(mailItem, new System.Net.Mime.ContentType("text/html; charset=us-ascii"));
3. Error message is : Cannot create an instance of the abstract class or interface 'Microsoft.Office.Interop.Outlook.Attachment'

4. Sample code below

   private void button1_Click(object sender, RibbonControlEventArgs e)
   {
       Explorer explorer = Globals.ThisAddIn.Application.ActiveExplorer();
       Selection selection = explorer.Selection;
   
       if (selection.Count > 0)   // Check that selection is not empty.
       {
           object selectedItem = selection[1];   // Index is one-based.
           MailItem mailItem = selectedItem as MailItem;
   
   
           if (mailItem != null)    // Check that selected item is a message.
           {
               System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage();
               message.To.Add("[e-mail]");
               message.Subject = "blah";
               message.From = new System.Net.Mail.MailAddress("[e-mail]");
               message.Body = "This is the message body";
   
                Attachment attach = new Attachment(mailItem, new System.Net.Mime.ContentType("text/html; charset=us-ascii"));
                message.Attachments.Add(attach);
               System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient("smlsmtp");
               smtp.Send(message);
   
           }
       }
   }
   

- SKR

---

如果您正在与Outlook集成，并从中读取MailItems，为什么要使用SMTP发送邮件？为什么不在Outlook中创建并发送呢？ - Kris Vandermotten

没有任何原因。这是我第一次尝试使用Outlook做任何事情。如果有更简单的方法来使用Outlook发送邮件，那么我想那会更好。我现在会去看看。如果您知道任何可以帮助我的资源，请告诉我。 - SKR

Answer 1

在做了更多的阅读和搜索之后，我终于找到了可行的方法。也许最困难的部分是第一行。

                try
                {
                    Outlook.MailItem tosend = (Outlook.MailItem)Globals.ThisAddIn.Application.CreateItem(Outlook.OlItemType.olMailItem);
                    tosend.Attachments.Add(mailItem);
                    tosend.To = "[e-mail]";
                    tosend.Subject = "test";
                    tosend.Body = "blah";
                    tosend.Save();
                    tosend.Send();
                }
                catch (Exception ex)
                {
                    Console.WriteLine("{0} Exception caught: ", ex);
                }

感谢 @Kris Vandermotten 指引我正确的方向。

- SKR