我一直在寻找这个问题的答案，但不依赖 Exchange 服务器，而是使用 IMAP 服务器。我不知道这是否超出了问题的范围，但我发现它在搜索“将已发送的 MailMessage 放入已发送的文件夹”，这首先是我的问题。
在我构建自己的解决方案的任何地方都没有找到直接答案：
我将 save 方法作为 smtpClient 的扩展来实现，所以我们将使用 .SendAndSaveMessageToIMAP() 而不是 .Send()。
public static class SmtpClientExtensions
{
static System.IO.StreamWriter sw = null;
static System.Net.Sockets.TcpClient tcpc = null;
static System.Net.Security.SslStream ssl = null;
static string path;
static int bytes = -1;
static byte[] buffer;
static System.Text.StringBuilder sb = new System.Text.StringBuilder();
static byte[] dummy;
/// <summary>
/// Communication with server
/// </summary>
/// <param name="command">The command beeing sent</param>
private static void SendCommandAndReceiveResponse(string command)
{
try
{
if (command != "")
{
if (tcpc.Connected)
{
dummy = System.Text.Encoding.ASCII.GetBytes(command);
ssl.Write(dummy, 0, dummy.Length);
}
else
{
throw new System.ApplicationException("TCP CONNECTION DISCONNECTED");
}
}
ssl.Flush();
buffer = new byte[2048];
bytes = ssl.Read(buffer, 0, 2048);
sb.Append(System.Text.Encoding.ASCII.GetString(buffer));
sw.WriteLine(sb.ToString());
sb = new System.Text.StringBuilder();
}
catch (System.Exception ex)
{
throw new System.ApplicationException(ex.Message);
}
}
/// <summary>
/// Saving a mail message before beeing sent by the SMTP client
/// </summary>
/// <param name="self">The caller</param>
/// <param name="imapServer">The address of the IMAP server</param>
/// <param name="imapPort">The port of the IMAP server</param>
/// <param name="userName">The username to log on to the IMAP server</param>
/// <param name="password">The password to log on to the IMAP server</param>
/// <param name="sentFolderName">The name of the folder where the message will be saved</param>
/// <param name="mailMessage">The message being saved</param>
public static void SendAndSaveMessageToIMAP(this System.Net.Mail.SmtpClient self, System.Net.Mail.MailMessage mailMessage, string imapServer, int imapPort, string userName, string password, string sentFolderName)
{
try
{
path = System.Environment.CurrentDirectory + "\\emailresponse.txt";
if (System.IO.File.Exists(path))
System.IO.File.Delete(path);
sw = new System.IO.StreamWriter(System.IO.File.Create(path));
tcpc = new System.Net.Sockets.TcpClient(imapServer, imapPort);
ssl = new System.Net.Security.SslStream(tcpc.GetStream());
ssl.AuthenticateAsClient(imapServer);
SendCommandAndReceiveResponse("");
SendCommandAndReceiveResponse(string.Format("$ LOGIN {1} {2} {0}", System.Environment.NewLine, userName, password));
using (var m = mailMessage.RawMessage())
{
m.Position = 0;
var sr = new System.IO.StreamReader(m);
var myStr = sr.ReadToEnd();
SendCommandAndReceiveResponse(string.Format("$ APPEND {1} (\\Seen) {{{2}}}{0}", System.Environment.NewLine, sentFolderName, myStr.Length));
SendCommandAndReceiveResponse(string.Format("{1}{0}", System.Environment.NewLine, myStr));
}
SendCommandAndReceiveResponse(string.Format("$ LOGOUT{0}", System.Environment.NewLine));
}
catch (System.Exception ex)
{
System.Diagnostics.Debug.WriteLine("error: " + ex.Message);
}
finally
{
if (sw != null)
{
sw.Close();
sw.Dispose();
}
if (ssl != null)
{
ssl.Close();
ssl.Dispose();
}
if (tcpc != null)
{
tcpc.Close();
}
}
self.Send(mailMessage);
}
}
public static class MailMessageExtensions
{
private static readonly System.Reflection.BindingFlags Flags = System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic;
private static readonly System.Type MailWriter = typeof(System.Net.Mail.SmtpClient).Assembly.GetType("System.Net.Mail.MailWriter");
private static readonly System.Reflection.ConstructorInfo MailWriterConstructor = MailWriter.GetConstructor(Flags, null, new[] { typeof(System.IO.Stream) }, null);
private static readonly System.Reflection.MethodInfo CloseMethod = MailWriter.GetMethod("Close", Flags);
private static readonly System.Reflection.MethodInfo SendMethod = typeof(System.Net.Mail.MailMessage).GetMethod("Send", Flags);
/// <summary>
/// A little hack to determine the number of parameters that we
/// need to pass to the SaveMethod.
/// </summary>
private static readonly bool IsRunningInDotNetFourPointFive = SendMethod.GetParameters().Length == 3;
/// <summary>
/// The raw contents of this MailMessage as a MemoryStream.
/// </summary>
/// <param name="self">The caller.</param>
/// <returns>A MemoryStream with the raw contents of this MailMessage.</returns>
public static System.IO.MemoryStream RawMessage(this System.Net.Mail.MailMessage self)
{
var result = new System.IO.MemoryStream();
var mailWriter = MailWriterConstructor.Invoke(new object[] { result });
SendMethod.Invoke(self, Flags, null, IsRunningInDotNetFourPointFive ? new[] { mailWriter, true, true } : new[] { mailWriter, true }, null);
result = new System.IO.MemoryStream(result.ToArray());
CloseMethod.Invoke(mailWriter, Flags, null, new object[] { }, null);
return result;
}
}
所以罗伯特·里德的例子会变成
using (var mailMessage = new MailMessage("fromaddress@blah.com", "toaddress@blah.com", "subject", "body"))
{
//Add an attachment just for the sake of it
Attachment doc = new Attachment(@"filePath");
doc.ContentId = "doc";
mailMessage.Attachments.Add(doc);
var smtpClient = new SmtpClient("SmtpHost")
{
EnableSsl = false,
DeliveryMethod = SmtpDeliveryMethod.Network
};
// Apply credentials
smtpClient.Credentials = new NetworkCredential("smtpUsername", "smtpPassword");
// Send
smtpClient.SendAndSaveMessageToIMAP(mailMessage, "imap.mail.com", 993, "imapUsername", "imapPassword", "SENT");
}