.NET Framework是否有办法通过端口465上的SSL SMTP服务器发送电子邮件？
通常的方式：
System.Net.Mail.SmtpClient _SmtpServer = new System.Net.Mail.SmtpClient("tempurl.org");
_SmtpServer.Port = 465;
_SmtpServer.EnableSsl = true;
_SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
_SmtpServer.Timeout = 5000;
_SmtpServer.UseDefaultCredentials = false;
MailMessage mail = new MailMessage();
mail.From = new MailAddress(from);
mail.To.Add(to);
mail.CC.Add(cc);
mail.Subject = subject;
mail.Body = content;
mail.IsBodyHtml = useHtml;
_SmtpServer.Send(mail);
超时：
System.Net Verbose: 0 : [1024] SmtpClient::.ctor(host=ssl0.ovh.net, port=465)
System.Net Information: 0 : [1024] Associating SmtpClient#64923656 with SmtpTransport#44624228
System.Net Verbose: 0 : [1024] Exiting SmtpClient::.ctor() -> SmtpClient#64923656
System.Net Information: 0 : [1024] Associating MailMessage#17654054 with Message#52727599
System.Net Verbose: 0 : [1024] SmtpClient#64923656::Send(MailMessage#17654054)
System.Net Information: 0 : [1024] SmtpClient#64923656::Send(DeliveryMethod=Network)
System.Net Information: 0 : [1024] Associating SmtpClient#64923656 with MailMessage#17654054
System.Net Information: 0 : [1024] Associating SmtpTransport#44624228 with SmtpConnection#14347911
System.Net Information: 0 : [1024] Associating SmtpConnection#14347911 with ServicePoint#51393439
System.Net.Sockets Verbose: 0 : [1024] Socket#26756241::Socket(InterNetwork#2)
System.Net.Sockets Verbose: 0 : [1024] Exiting Socket#26756241::Socket()
System.Net.Sockets Verbose: 0 : [1024] Socket#23264094::Socket(InterNetworkV6#23)
System.Net.Sockets Verbose: 0 : [1024] Exiting Socket#23264094::Socket()
System.Net.Sockets Verbose: 0 : [1024] Socket#26756241::Connect(20:465#337754884)
System.Net.Sockets Verbose: 0 : [1024] Exiting Socket#26756241::Connect()
System.Net.Sockets Verbose: 0 : [1024] Socket#23264094::Close()
System.Net.Sockets Verbose: 0 : [1024] Socket#23264094::Dispose()
System.Net.Sockets Verbose: 0 : [1024] Exiting Socket#23264094::Close()
System.Net Information: 0 : [1024] Associating SmtpConnection#14347911 with SmtpPooledStream#14303791
System.Net.Sockets Verbose: 0 : [1024] Socket#26756241::Receive()
System.Net.Sockets Verbose: 0 : [2404] Socket#26756241::Dispose()
System.Net.Sockets Error: 0 : [1024] Exception in the Socket#26756241::Receive - A blocking operation was interrupted by a call to WSACancelBlockingCall
System.Net.Sockets Verbose: 0 : [1024] Exiting Socket#26756241::Receive() -> 0#0
System.Net Error: 0 : [1024] Exception in the SmtpClient#64923656::Send - Unable to read data from the transport connection: A blocking operation was interrupted by a call to WSACancelBlockingCall.
System.Net Error: 0 : [1024] at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.DelegatedStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at System.Net.BufferedReadStream.Read(Byte[] buffer, Int32 offset, Int32 count)
at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine)
at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller)
at System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port)
at System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port)
at System.Net.Mail.SmtpClient.GetConnection()
at System.Net.Mail.SmtpClient.Send(MailMessage message)
System.Net Verbose: 0 : [1024] Exiting SmtpClient#64923656::Send()
System.Net Information: 0 : [1024] Associating MailMessage#49584532 with Message#19699911
我google了一下，发现System.Net.Mail支持端口587上的连接（显式SSL的默认端口，未加密，然后发出STARTDLS，然后切换到加密连接：RFC 2228），但不支持隐式SSL （整个连接包装在SSL层中）...
答案 0 :(得分：33)
以下是如何通过GMail发送电子邮件的示例，该电子邮件也使用SSL / 465。稍微调整下面的代码就可以了！
using System.Web.Mail;
using System;
public class MailSender
{
public static bool SendEmail(
string pGmailEmail,
string pGmailPassword,
string pTo,
string pSubject,
string pBody,
System.Web.Mail.MailFormat pFormat,
string pAttachmentPath)
{
try
{
System.Web.Mail.MailMessage myMail = new System.Web.Mail.MailMessage();
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/smtpserver",
"smtp.gmail.com");
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/smtpserverport",
"465");
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/sendusing",
"2");
//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.
//When using this option you have to provide the user name and password
//through the sendusername and sendpassword fields.
//- cdoNTLM, value 2. The current process security context is used to
// authenticate with the service.
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate","1");
//Use 0 for anonymous
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/sendusername",
pGmailEmail);
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/sendpassword",
pGmailPassword);
myMail.Fields.Add
("http://schemas.microsoft.com/cdo/configuration/smtpusessl",
"true");
myMail.From = pGmailEmail;
myMail.To = pTo;
myMail.Subject = pSubject;
myMail.BodyFormat = pFormat;
myMail.Body = pBody;
if (pAttachmentPath.Trim() != "")
{
MailAttachment MyAttachment =
new MailAttachment(pAttachmentPath);
myMail.Attachments.Add(MyAttachment);
myMail.Priority = System.Web.Mail.MailPriority.High;
}
System.Web.Mail.SmtpMail.SmtpServer = "smtp.gmail.com:465";
System.Web.Mail.SmtpMail.Send(myMail);
return true;
}
catch (Exception ex)
{
throw;
}
}
}
答案 1 :(得分：13)
我参加这个派对已经迟到了，但是我会为任何可能对替代方案感兴趣的路人提供我的方法。
如前所述，System.Net.Mail SmtpClient类不支持隐式SSL 。它支持显式SSL ，它需要通过端口25与SMTP服务器进行不安全的连接，以便协商传输级别安全性（TLS）。我用这个微妙的here写了关于我的艰辛的博客。
简而言之，SMTP over Implict SSL端口465要求在连接到SMTP服务器之前协商TLS 。我没有编写.Net SMTPS实现，而是使用了名为Stunnel的实用程序。这是一项小型服务，可让您通过SSL将本地端口上的流量重定向到远程端口。
免责声明：Stunnel使用部分OpenSSL库，该库最近在所有主要科技新闻媒体上发布了一个高调的漏洞。我相信最新版本使用修补后的OpenSSL，但请自担风险使用。
安装实用程序后，在配置文件中添加一小部分：
; Example SSL client mode services
[my-smtps]
client = yes
accept = 127.0.0.1:465
connect = mymailserver.com:465
...指示Stunnel服务在端口465上将本地请求重新路由到端口465到我的邮件服务器。这通过TLS发生，它满足另一端的SMTP服务器。
使用此实用程序，以下代码将通过端口465成功传输：
using System;
using System.Net;
using System.Net.Mail;
namespace RSS.SmtpTest
{
class Program
{
static void Main( string[] args )
{
try {
using( SmtpClient smtpClient = new SmtpClient( "localhost", 465 ) ) { // <-- note the use of localhost
NetworkCredential creds = new NetworkCredential( "username", "password" );
smtpClient.Credentials = creds;
MailMessage msg = new MailMessage( "joe@schmoe.com", "jane@schmoe.com", "Test", "This is a test" );
smtpClient.Send( msg );
}
}
catch( Exception ex ) {
Console.WriteLine( ex.Message );
}
}
}
}
因此，这里的优点是您可以使用Implict SSL和端口465作为安全协议，同时仍然使用框架内置的发送邮件方法。缺点是它需要使用第三方服务，除了这个特定的功能之外，它可能没什么用处。
答案 2 :(得分：11)
它适用于System.Web.Mail（标记为已废弃）：
private const string SMTP_SERVER = "http://schemas.microsoft.com/cdo/configuration/smtpserver";
private const string SMTP_SERVER_PORT = "http://schemas.microsoft.com/cdo/configuration/smtpserverport";
private const string SEND_USING = "http://schemas.microsoft.com/cdo/configuration/sendusing";
private const string SMTP_USE_SSL = "http://schemas.microsoft.com/cdo/configuration/smtpusessl";
private const string SMTP_AUTHENTICATE = "http://schemas.microsoft.com/cdo/configuration/smtpauthenticate";
private const string SEND_USERNAME = "http://schemas.microsoft.com/cdo/configuration/sendusername";
private const string SEND_PASSWORD = "http://schemas.microsoft.com/cdo/configuration/sendpassword";
System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
mail.Fields[SMTP_SERVER] = "tempurl.org";
mail.Fields[SMTP_SERVER_PORT] = 465;
mail.Fields[SEND_USING] = 2;
mail.Fields[SMTP_USE_SSL] = true;
mail.Fields[SMTP_AUTHENTICATE] = 1;
mail.Fields[SEND_USERNAME] = "username";
mail.Fields[SEND_PASSWORD] = "password";
System.Web.Mail.SmtpMail.Send(mail);
您对过时的命名空间使用情况有何看法？
答案 3 :(得分：8)
尝试检查这个免费的开源替代品 https://www.nuget.org/packages/AIM 它是免费使用和开源的，并使用与System.Net.Mail使用完全相同的方式 要向隐式ssl端口发送电子邮件，您可以使用以下代码
public static void SendMail()
{
var mailMessage = new MimeMailMessage();
mailMessage.Subject = "test mail";
mailMessage.Body = "hi dude!";
mailMessage.Sender = new MimeMailAddress("you@gmail.com", "your name");
mailMessage.To.Add(new MimeMailAddress("yourfriend@gmail.com", "your friendd's name"));
// You can add CC and BCC list using the same way
mailMessage.Attachments.Add(new MimeAttachment("your file address"));
//Mail Sender (Smtp Client)
var emailer = new SmtpSocketClient();
emailer.Host = "your mail server address";
emailer.Port = 465;
emailer.SslType = SslMode.Ssl;
emailer.User = "mail sever user name";
emailer.Password = "mail sever password" ;
emailer.AuthenticationMode = AuthenticationType.Base64;
// The authentication types depends on your server, it can be plain, base 64 or none.
//if you do not need user name and password means you are using default credentials
// In this case, your authentication type is none
emailer.MailMessage = mailMessage;
emailer.OnMailSent += new SendCompletedEventHandler(OnMailSent);
emailer.SendMessageAsync();
}
// A simple call back function:
private void OnMailSent(object sender, AsyncCompletedEventArgs asynccompletedeventargs)
{
if (e.UserState!=null)
Console.Out.WriteLine(e.UserState.ToString());
if (e.Error != null)
{
MessageBox.Show(e.Error.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
else if (!e.Cancelled)
{
MessageBox.Show("Send successfull!", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
答案 4 :(得分：6)
在VB.NET中尝试连接到465上的Rackspace的SSL端口时遇到了同样的问题（需要隐式SSL）。我使用了https://www.nuget.org/packages/MailKit/来成功连接。
以下是HTML电子邮件的示例。
Imports MailKit.Net.Smtp
Imports MailKit
Imports MimeKit
Sub somesub()
Dim builder As New BodyBuilder()
Dim mail As MimeMessage
mail = New MimeMessage()
mail.From.Add(New MailboxAddress("", c_MailUser))
mail.To.Add(New MailboxAddress("", c_ToUser))
mail.Subject = "Mail Subject"
builder.HtmlBody = "<html><body>Body Text"
builder.HtmlBody += "</body></html>"
mail.Body = builder.ToMessageBody()
Using client As New SmtpClient
client.Connect(c_MailServer, 465, True)
client.AuthenticationMechanisms.Remove("XOAUTH2") ' Do not use OAUTH2
client.Authenticate(c_MailUser, c_MailPassword) ' Use a username / password to authenticate.
client.Send(mail)
client.Disconnect(True)
End Using
End Sub
答案 5 :(得分：4)
如果是隐式SSL，看起来无法使用System.Net.Mail完成，并且目前尚不支持。
要检查它是否为隐式SSL，请尝试this.
答案 6 :(得分：4)
您也可以通过端口465进行连接，但由于System.Net.Mail命名空间的某些限制，您可能需要更改代码。这是因为命名空间不提供进行隐式SSL连接的能力。这在http://blogs.msdn.com/b/webdav_101/archive/2008/06/02/system-net-mail-with-ssl-to-authenticate-against-port-465.aspx讨论。
可以在不必使用现在过时的System.Web.Mail命名空间的情况下进行隐式连接，但您必须访问Microsoft CDO（协作数据对象）。我在另一个讨论中提供了一个如何使用CDO的示例（GMail SMTP via C# .Net errors on all ports）。
希望这有帮助！
答案 7 :(得分：2)
我知道我加入讨论的时间较晚，但我认为这对其他人有用。
我想避免被弃用的东西，经过大量的摆弄后，我找到了一种简单的方法发送到需要隐式SSL的服务器：使用NuGet并将MailKit package添加到项目中。 （我使用VS2017目标.NET 4.6.2，但它应该适用于较低的.NET版本......）
然后你只需要做这样的事情：
using MailKit.Net.Smtp;
using MimeKit;
var client = new SmtpClient();
client.Connect("server.name", 465, true);
// Note: since we don't have an OAuth2 token, disable the XOAUTH2 authentication mechanism.
client.AuthenticationMechanisms.Remove ("XOAUTH2");
if (needsUserAndPwd)
{
// Note: only needed if the SMTP server requires authentication
client.Authenticate (user, pwd);
}
var msg = new MimeMessage();
msg.From.Add(new MailboxAddress("sender@ema.il"));
msg.To .Add(new MailboxAddress("target@ema.il"));
msg.Subject = "This is a test subject";
msg.Body = new TextPart("plain") {
Text = "This is a sample message body"
};
client.Send(msg);
client.Disconnect(true);
当然，您也可以调整它以使用显式SSL或根本没有传输安全性。
答案 8 :(得分：1)
如
中的评论所述 使用System.Net.Mail，使用端口25而不是465：
您必须设置SSL = true和Port = 25。服务器响应来自未受保护的25的请求，然后抛出与受保护的465的连接。
答案 9 :(得分：0)
如果对此代码有任何疑问，请提出您的问题（这里的gmail端口号是587）
// code to Send Mail
// Add following Lines in your web.config file
// <system.net>
// <mailSettings>
// <smtp>
// <network host="smtp.gmail.com" port="587" userName="xxx@gmail.com" password="yyy" defaultCredentials="false"/>
// </smtp>
// </mailSettings>
// </system.net>
// Add below lines in your config file inside appsetting tag <appsetting></appsetting>
// <add key="emailFromAddress" value="xxxx@gmail.com"/>
// <add key="emailToAddress" value="xxxxxxx@gmail.com"/>
// <add key="EmailSsl" value="true"/>
// Namespace Used
using System.Net.Mail;
public static bool SendingMail(string subject, string content)
{
// getting the values from config file through c#
string fromEmail = ConfigurationSettings.AppSettings["emailFromAddress"];
string mailid = ConfigurationSettings.AppSettings["emailToAddress"];
bool useSSL;
if (ConfigurationSettings.AppSettings["EmailSsl"] == "true")
{
useSSL = true;
}
else
{
useSSL = false;
}
SmtpClient emailClient;
MailMessage message;
message = new MailMessage();
message.From = new MailAddress(fromEmail);
message.ReplyTo = new MailAddress(fromEmail);
if (SetMailAddressCollection(message.To, mailid))
{
message.Subject = subject;
message.Body = content;
message.IsBodyHtml = true;
emailClient = new SmtpClient();
emailClient.EnableSsl = useSSL;
emailClient.Send(message);
}
return true;
}
// if you are sending mail in group
private static bool SetMailAddressCollection(MailAddressCollection toAddresses, string mailId)
{
bool successfulAddressCreation = true;
toAddresses.Add(new MailAddress(mailId));
return successfulAddressCreation;
}
答案 10 :(得分：0)
对于gmail这些设置适用于我，ServicePointManager.SecurityProtocol行是必要的。因为我已经设置了2步验证，所以我需要从google app password generator获取应用密码。
SmtpClient mailer = new SmtpClient();
mailer.Host = "smtp.gmail.com";
mailer.Port = 587;
mailer.EnableSsl = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
答案 11 :(得分：0)
为了扩展Idriss的答案，这是我的静态方法，就像冠军一样：
using System.Web.Mail;
public static void SendEmail(String Subject, String sMessage, String EmailAddress, String STMPServer, int SMTPPort, String UserName = "", String Password = null, Boolean IsSecure = true, Boolean IsHTML = true, String FromAddress = "no-reply@contoso.com") {
string SMTP_SERVER = "http://schemas.microsoft.com/cdo/configuration/smtpserver";
string SMTP_SERVER_PORT = "http://schemas.microsoft.com/cdo/configuration/smtpserverport";
string SEND_USING = "http://schemas.microsoft.com/cdo/configuration/sendusing";
string SMTP_USE_SSL = "http://schemas.microsoft.com/cdo/configuration/smtpusessl";
string SMTP_AUTHENTICATE = "http://schemas.microsoft.com/cdo/configuration/smtpauthenticate";
string SEND_USERNAME = "http://schemas.microsoft.com/cdo/configuration/sendusername";
string SEND_PASSWORD = "http://schemas.microsoft.com/cdo/configuration/sendpassword";
MailMessage mail = new MailMessage();
mail.Fields[SMTP_SERVER] = STMPServer;
mail.Fields[SMTP_SERVER_PORT] = SMTPPort;
mail.Fields[SEND_USING] = 2;
mail.Fields[SMTP_USE_SSL] = IsSecure;
if(!String.IsNullOrEmpty(UserName) && !String.IsNullOrEmpty(Password))
{
mail.Fields[SMTP_AUTHENTICATE] = 1;
mail.Fields[SEND_USERNAME] = UserName;
mail.Fields[SEND_PASSWORD] = Password;
}
else
{
mail.Fields[SMTP_AUTHENTICATE] = 0;
}
mail.From = FromAddress;
mail.To = EmailAddress;
mail.Subject = Subject;
if (IsHTML)
{
mail.BodyFormat = MailFormat.Html;
}
else
{
mail.BodyFormat = MailFormat.Text;
}
mail.Body = sMessage;
SmtpMail.Send(mail);
}