GMail SMTP 通过所有端口上的 C# .Net 错误
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GMail SMTP via C# .Net errors on all ports
提问by Paul
I've been trying for a whlie on this, and have so far been failing miserably. My most recent attempt was lifted from this stack code here: Sending email through Gmail SMTP server with C#, but I've tried all the syntax I could find here on stack and elsewhere. My code currently is:
我一直在为此努力，但到目前为止一直失败。我最近的尝试是从这里的堆栈代码中提取的： 使用 C# 通过 Gmail SMTP 服务器发送电子邮件，但我已经尝试了在堆栈和其他地方可以找到的所有语法。我的代码目前是：
var client = new SmtpClient("smtp.gmail.com", 587)
{
Credentials = new NetworkCredential("[email protected]", "mypass"),
EnableSsl = true
};
client.Send("[email protected]","[email protected]","Test", "test message");
Running that code gives me an immediate exception "Failure sending mail" that has an innerexeption "unable to connect to the remote server".
运行该代码会给我一个即时异常“发送邮件失败”，其中包含“无法连接到远程服务器”的内部异常。
If I change the port to 465 (as gmail docs suggest), I get a timeout every time.
如果我将端口更改为 465（如 gmail 文档所建议的那样），我每次都会超时。
I've read that 465 isn't a good port to use, so I'm wondering what the deal is w/ 587 giving me failure to connect. My user and pass are right. I've read that I have to have POP service setup on my gmail account, so I did that. No avail.
我读过 465 不是一个好的端口，所以我想知道 587 是什么交易，导致我无法连接。我的用户和通行证是对的。我读到我必须在我的 gmail 帐户上设置 POP 服务，所以我这样做了。徒劳无功。
I was originally trying to get this working for my branded GMail account, but after running into the same problems w/ that I thoughtgoing w/ my regular gmail account would be easier... so far that's not the case.
我最初试图让它为我的品牌 GMail 帐户工作，但在遇到相同的问题后，我认为使用我的常规 Gmail 帐户会更容易......到目前为止情况并非如此。
采纳答案by Daniel Svalefelt
I tried your code, and it works prefectly with port 587, but not with 465.
我试过你的代码，它在 587 端口上工作得很好，但在 465 上不工作。
Have you checked the fire wall? Try from the command line "Telnet smtp.gmail.com 587" If you get "220 mx.google.com ESMTP...." back, then the port is open. If not, it is something that blocks you call.
你检查过防火墙吗？尝试从命令行“Telnet smtp.gmail.com 587”如果返回“220 mx.google.com ESMTP....”，则端口已打开。如果没有，它会阻止您调用。
Daniel
丹尼尔
回答by Daniel Svalefelt
I implemented an email client sometime back that could talk to gmail on both 587 and 465...
我曾经在某个时候实现了一个电子邮件客户端，它可以在 587 和 465 上与 gmail 通信......
Port 25 is the normal unencrypted pop port; not available on gmail.
端口 25 是正常的未加密 pop 端口；在 Gmail 上不可用。
The other two ports have encryption; 587 uses TLS, 465 uses SSL.
另外两个端口有加密；587 使用 TLS，465 使用 SSL。
To use 587 you should set SmtpClient.EnableSsl = true.
要使用 587，您应该设置 SmtpClient.EnableSsl = true。
465 wont work with SmtpClient, it will work with the deprecated class SmtpMail instead.
465 无法与 SmtpClient 一起使用，它将与已弃用的类 SmtpMail 一起使用。
回答by erdenetsogt
Your private network's firewall blocked the ports 587 and 465. You can use default port 25 or enable there ports on firewall
您的专用网络的防火墙阻止了端口 587 和 465。您可以使用默认端口 25 或启用防火墙上的端口
回答by Bryan Allred
I ran in to this problem a while ago as well. The problem is that SmtpClient does not support implicit SSL connections, but does support explicit connections (System.Net.Mail with SSL to authenticate against port 465). The previous class of MailMessage (I believe .Net 1.0) did support this but has long been obsolete.
不久前我也遇到了这个问题。问题是 SmtpClient 不支持隐式 SSL 连接，但支持显式连接（System.Net.Mail with SSL to authentication against port 465）。以前的 MailMessage 类（我相信 .Net 1.0）确实支持这一点，但早已过时了。
My answer was to call the CDO (Collaborative Data Objects) (http://support.microsoft.com/kb/310212) directly through COM using something like the following:
我的答案是直接通过 COM调用 CDO（协作数据对象）（http://support.microsoft.com/kb/310212），使用如下所示：
/// <summary>
/// Send an electronic message using the Collaboration Data Objects (CDO).
/// </summary>
/// <remarks>http://support.microsoft.com/kb/310212</remarks>
private void SendTestCDOMessage()
{
try
{
string yourEmail = "[email protected]";
CDO.Message message = new CDO.Message();
CDO.IConfiguration configuration = message.Configuration;
ADODB.Fields fields = configuration.Fields;
Console.WriteLine(String.Format("Configuring CDO settings..."));
// Set configuration.
// sendusing: cdoSendUsingPort, value 2, for sending the message using the network.
// smtpauthenticate: Specifies the mechanism used when authenticating to an SMTP service over the network.
// Possible values are:
// - cdoAnonymous, value 0. Do not authenticate.
// - cdoBasic, value 1. Use basic clear-text authentication. (Hint: This requires the use of "sendusername" and "sendpassword" fields)
// - cdoNTLM, value 2. The current process security context is used to authenticate with the service.
ADODB.Field field = fields["http://schemas.microsoft.com/cdo/configuration/smtpserver"];
field.Value = "smtp.gmail.com";
field = fields["http://schemas.microsoft.com/cdo/configuration/smtpserverport"];
field.Value = 465;
field = fields["http://schemas.microsoft.com/cdo/configuration/sendusing"];
field.Value = CDO.CdoSendUsing.cdoSendUsingPort;
field = fields["http://schemas.microsoft.com/cdo/configuration/smtpauthenticate"];
field.Value = CDO.CdoProtocolsAuthentication.cdoBasic;
field = fields["http://schemas.microsoft.com/cdo/configuration/sendusername"];
field.Value = yourEmail;
field = fields["http://schemas.microsoft.com/cdo/configuration/sendpassword"];
field.Value = "YourPassword";
field = fields["http://schemas.microsoft.com/cdo/configuration/smtpusessl"];
field.Value = "true";
fields.Update();
Console.WriteLine(String.Format("Building CDO Message..."));
message.From = yourEmail;
message.To = yourEmail;
message.Subject = "Test message.";
message.TextBody = "This is a test message. Please disregard.";
Console.WriteLine(String.Format("Attempting to connect to remote server..."));
// Send message.
message.Send();
Console.WriteLine("Message sent.");
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
Do not forget to browse through your COM references and add the "Microsoft CDO for Windows 200 Library" which should add two references: ADODB, and CDO.
不要忘记浏览您的 COM 引用并添加“Microsoft CDO for Windows 200 库”，它应该添加两个引用：ADODB 和 CDO。
回答by kmote
I had the same problem, but was not at liberty to alter my company's firewall restrictions. Based on the one of the notes on this Google doc, along with erdenetsogt's answer above, I tried using port 25 and it worked. (At first I was concerned that using port 25 might imply that message might not be encrypted; so I set EnableSSL to false, which caused gmail to reject it because the StartTLS was never called. This leads me to believe that gmail is enforcing the Explicit SSL, even over port 25).
我遇到了同样的问题，但不能随意更改我公司的防火墙限制。根据此 Google doc上的注释之一以及上面 erdenetsogt 的回答，我尝试使用端口 25 并且它有效。（起初我担心使用端口 25 可能意味着该消息可能未加密；所以我将 EnableSSL 设置为 false，这导致 gmail 拒绝它，因为从未调用过 StartTLS。这让我相信 gmail 正在执行显式SSL，甚至通过端口 25）。
回答by Fevzi Apayd?n
Try this link http://www.google.com/accounts/DisplayUnlockCaptchaon server.
在服务器上试试这个链接http://www.google.com/accounts/DisplayUnlockCaptcha。
Business Gmail accounts, (or normal gmail accounts don't sure about this one) demands a DisplayUnlockCaptcha for the very first time.
商业 Gmail 帐户（或普通 Gmail 帐户不确定这个帐户）第一次需要 DisplayUnlockCaptcha。
回答by Debashis Chowdhury
There are two ways to do SMTP over SSL: Explicit and Implicit. Explicit means you connect to a normal SMTP port (usually 25 or 587) in plaintext, then issue the “starttls” command to switch to SSL-mode. Implicit means you connect to a port that expects everything to be SSL (usually 465).
有两种方法可以通过 SSL 执行 SMTP：显式和隐式。显式意味着您以明文形式连接到普通 SMTP 端口（通常为 25 或 587），然后发出“starttls”命令以切换到 SSL 模式。隐式意味着您连接到一个期望所有内容都是 SSL（通常是 465）的端口。
Asp.net use “System.Net.Mail.SmtpClient()” to send Email. The main problem is SmtpClient does not support implicit SSL connections, but does support explicit connections (System.Net.Mail with SSL to authenticate against port 465). So, if the mail server(SMTP) do not support Explicit connection, it fails to send email and show messages like “Connection timeout“, “The message could not be sent to the SMTP server. The transport error code was 0x80040217. The server response was not available” etc.
Asp.net 使用“System.Net.Mail.SmtpClient()”来发送电子邮件。主要问题是 SmtpClient 不支持隐式 SSL 连接，但支持显式连接（System.Net.Mail 使用 SSL 对端口 465 进行身份验证）。因此，如果邮件服务器（SMTP）不支持显式连接，则无法发送电子邮件并显示“连接超时”、“消息无法发送到 SMTP 服务器”等消息。传输错误代码是 0x80040217。服务器响应不可用”等。
To solve this issue in ASP.net we can use the Collaboration Data Objects (CDO) for Windows 2000 library (Cdosys.dll) to send an e-mail message with attachments. Microsoft Outlook use this DLL to send email. In your ASP.net solution, you have to add referance “Microsoft CDO for windows 2000 Library“. It will add two marked dll in Bin folder.
为了解决 ASP.net 中的这个问题，我们可以使用 Windows 2000 库 (Cdosys.dll) 的协作数据对象 (CDO) 来发送带有附件的电子邮件。Microsoft Outlook 使用此 DLL 发送电子邮件。在您的 ASP.net 解决方案中，您必须添加参考“Microsoft CDO for windows 2000 Library”。它将在 Bin 文件夹中添加两个标记的 dll。
Now do the bellow code in C#.net:
现在在 C#.net 中执行以下代码：
public static void SendMail(string FromName, string FromEmail, string ReceiverEmail, string CC, string BCC, string subj, string Mssg)
{
const var cdoSendUsingPort = 2;
const var cdoBasicAuth = 1;
const var cdoTimeout = 60;
var mailServer = "mail.XXXXXXX.net";
var SMTPport = 465;
var mailusername = "[email protected]";
var mailpassword = "PPPPXXXX";
var objEmail = CreateObject("CDO.Message");
var objConf = objEmail.Configuration;
var objFlds = objConf.Fields;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = cdoSendUsingPort;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = mailServer;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = SMTPport;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = true;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout") = cdoTimeout;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = cdoBasicAuth;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = mailusername;
objFlds.Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = mailpassword;
objFlds.Update();
objEmail.To = ReceiverEmail;
objEmail.From = FromEmail;
objEmail.CC = CC;
objEmail.BCC = BCC;
objEmail.Subject = subj;
objEmail.HTMLBody = Mssg;
objEmail.Send();
}
In VB.net
在 VB.net 中
Public Shared Sub SendMail(ByVal FromName As String, ByVal FromEmail As String, ByVal ReceiverEmail As String, ByVal CC As String, ByVal BCC As String, ByVal subj As String, ByVal Mssg As String)
''#################Sending Email##########################
Const cdoSendUsingPort = 2 ' Send the message using SMTP
Const cdoBasicAuth = 1 ' Clear-text authentication
Const cdoTimeout = 60 ' Timeout for SMTP in seconds
Dim mailServer = "mail.XXXXXXX.net"
Dim SMTPport = 465
Dim mailusername = "[email protected]"
Dim mailpassword = "PPPPXXXX"
Dim objEmail = CreateObject("CDO.Message")
Dim objConf = objEmail.Configuration
Dim objFlds = objConf.Fields
With objFlds
.Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = cdoSendUsingPort
.Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = mailServer
.Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = SMTPport
.Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = True
.Item("http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout") = cdoTimeout
.Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = cdoBasicAuth
.Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = mailusername
.Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = mailpassword
.Update()
End With
objEmail.To = ReceiverEmail
objEmail.From = FromEmail
objEmail.CC = CC
objEmail.BCC = BCC
objEmail.Subject = subj
objEmail.HTMLBody = Mssg
'objEmail.AddAttachment "C:\report.pdf"
objEmail.Send()
End Sub
Referance: Original postImplicit & Explicit SMTP http://help.fogcreek.com/9002/using-an-smtp-server-with-ssluse the Cdosys.dll library to send an e-mail message with attachments https://support.microsoft.com/en-us/help/310212/how-to-use-the-cdosys-dll-library-to-send-an-e-mail-message-with-attac
参考： 原帖Implicit & Explicit SMTP http://help.fogcreek.com/9002/using-an-smtp-server-with-ssl使用 Cdosys.dll 库发送带有附件的电子邮件https:// support.microsoft.com/en-us/help/310212/how-to-use-the-cdosys-dll-library-to-send-an-e-mail-message-with-attac
