c# 通过exchange 2K7使用smtp发送邮件

Question

以下代码在通过 gmail 的 smtp 发送时有效，但在通过 Exchange 2K7 发送时无效。 在同一台机器上，我有 Outlook Express，它确实成功地通过交换发送。 我在代码中使用与 Outlook Express 中相同的配置，但不断收到错误：

The SMTP server requires a secure connection or the client was not authenticated.
The server response was: 5.7.1 Client was not authenticated.
Stack:    at System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response)
   at System.Net.Mail.MailCommand.Send ...

Ssl 设置为 true。

这是代码：

//create new MailMessage
mailmessage = new MailMessage(definition.From, definition.To);
mailmessage.ReplyToList.Add(definition.From);
mailmessage.IsBodyHtml = true;
mailmessage.SubjectEncoding = System.Text.Encoding.UTF8;
mailmessage.BodyEncoding = System.Text.Encoding.UTF8;
mailmessage.Subject = definition.Subject;
mailmessage.Body = definition.Body;

mailmessage = MessageBody.CompleteMessage(mailmessage, definition);

//send MailMessage
//get smtpclient
SmtpClient smtp = null;

if (smtp == null)
{
//create, init
smtp = new SmtpClient(definition.Server, definition.Port)
{
    Credentials = new NetworkCredential(definition.Uid, definition.Pwd),
    EnableSsl = definition.Ssl,
    DeliveryMethod = SmtpDeliveryMethod.Network
};

}
ServicePointManager.ServerCertificateValidationCallback = delegate(object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; };
smtp.Send(mailmessage);

更新：当我取出回调线并尝试发送时，我收到此错误：

Exception: The remote certificate is invalid according to the validation procedure.. Stack:    at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
   at System.Net.TlsStream.CallProcessAuthentication(Object state)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
   at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.PooledStream.Write(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.Mail.SmtpConnection.Flush()
   at System.Net.Mail.ReadLinesCommand.Send(SmtpConnection conn)
   at System.Net.Mail.EHelloCommand.Send(SmtpConnection conn, String domain)
   at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
   at System.Net.Mail.SmtpTransport.GetConnection(ServicePoint servicePoint)
   at System.Net.Mail.SmtpClient.GetConnection()
   at System.Net.Mail.SmtpClient.Send(MailMessage message)

Answer 1

找到了一个很好的解决方案。不要尝试在 Exchange 2K7 及更高版本上使用 smtp。请改用 EWS（Exchange Web 服务）。

步骤如下：

1. 从 http://www.microsoft 下载 EWS 托管 API .com/download/en/details.aspx?id=13480
2. 安装它将
3. 对 Microsoft.Exchange.WebServices.dll 的引用添加到您的项目中。您可以在 C:\Program Files (x86)\Microsoft\Exchange\Web Services\1.1 中找到它

4. 使用下面的示例代码作为参考。

   使用 Microsoft.Exchange.WebServices.Data；

   using System.Security.Cryptography.X509Certificates;

...

ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2007_SP1);

service.Url = new Uri(@"https://"+[Your exchange computer name like: abc.domain.com]+"/EWS/Exchange.asmx"); 

//if have the ip you can get the computer name using the nslookup utility in command line. ->nslookup 192.168.0.90 

ServicePointManager.ServerCertificateValidationCallback =
                    delegate(Object obj, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
                    {
                        return true;
                    };

service.Credentials = new WebCredentials([User name: either email or domain account-but without the domain\], "password");

EmailMessage mailmessage = new EmailMessage(service);

mailmessage.From="[email protected]";

mailmessage.ToRecipients.Add("[email protected]");

mailmessage.Subject = "Hello";

mailmessage.Body = "World";

mailmessage.Body.BodyType = BodyType.HTML; //or text

mailmessage.Send();

希望对您有帮助。

Answer 2

即兴看来，您所做的一切都是正确的。我的两个建议是在黑暗中刺探，但您可能需要仔细看看：

因为您得到： The SMTP 服务器需要安全连接或客户端未经身份验证。服务器响应为：5.7.1 客户端未经过身份验证。 Stack: at System.Net.Mail.MailCommand ... 我将不得不假设 Exchange 服务器在解释它接收的数据包时遇到问题。

1) 这可能是由于 SSL 加密造成的。我会仔细检查您是否需要 SSL。您可以在不使用 SSL 的情况下发送（尽管不建议）用户名和密码。这将是一个糟糕的服务器设置，但这可能超出您的控制范围。

2) 您还进行证书验证回调。这是额外的 SMTP 验证层，可能与 SSL 数据包发生冲突。不用那行就可以发送邮件吗？

我希望这些可以推动您找到真正的答案。