CLI¶

In previous section, I introduced how to send email in a simple Managed C++/CLI project. In this section, I will introduce the SSL connection.

Sections:

SSL and TLS Introduction
TLS 1.2
[Managed C++/CLI Exmaple - SSL/TLS]
[Managed C++ Example - Send email over direct SSL on 465 port]
[Managed C++ Example - Send email over TLS on 25 or 587 port]

SSL and TLS Introduction¶

SSL connection encrypts data between the SMTP component and SMTP server to protects user, password and email content in TCP/IP level. Now this technology is commonly used and many SMTP servers are deployed with SSL such as Gmail, Yahoo and Hotmail. There are two ways to deploy SSL on SMTP server:

Explicit SSL (TLS)

Using STARTTLS command to switch SSL channel on normal SMTP port (25 or 587);
Implicit SSL

Deploying SSL on another port (465 or other port, you may query it from your server administrator

EASendMail SMTP component supports both ways. The connection can be specified by EASendMail.SmtpConnectType enumeration. Please see the following example code.

TLS 1.2¶

TLS is the successor of SSL, more and more SMTP servers require TLS 1.2 encryption now.

If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2, and you got connection error with SSL/TLS connection, you need to enable TLS 1.2 protocol in your operating system like this:

Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012

[Managed C++/CLI Exmaple - SSL/TLS]¶

// Send email by normal TCP/IP without SSL connection
SmtpServer^ oServer = gcnew SmtpServer("localhost 25");
oServer->ConnectType = SmtpConnectType::ConnectNormal;

// Send email by SSL connection with STARTTLS command switching
SmtpServer^ oServer = gcnew SmtpServer("localhost 25");
oServer->ConnectType = SmtpConnectType::ConnectSTARTTLS;

// Send email by SSL connection with direct SSL.
SmtpServer^ oServer = gcnew SmtpServer("localhost 465");
oServer->ConnectType = SmtpConnectType::ConnectDirectSSL;

// Send email by SSL connection with auto-detect.
// If port is 25 or 587, STARTTLS SSL will be used; otherwise direct SSL will be used.
SmtpServer^ oServer = gcnew SmtpServer("localhost 465");
oServer->ConnectType = SmtpConnectType::ConnectSSLAuto

SmtpServer^ oServer = gcnew SmtpServer("localhost 25");
oServer->ConnectType = SmtpConnectType::ConnectSSLAuto;

// If server supports SSL/TLS, then SSL/TLS is used, otherwise normal TCP is used.
SmtpServer^ oServer = gcnew SmtpServer("localhost 25");
oServer->ConnectType = SmtpConnectType::ConnectTryTLS;

SmtpServer^ oServer = gcnew SmtpServer("localhost 587");
oServer->ConnectType = SmtpConnectType::ConnectTryTLS;

Note

Remarks: All of samples in this section are based on first section: A simple Managed C++/CLI project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference of EASendMail to your project.

[Managed C++ Example - Send email over direct SSL on 465 port]¶

The following example codes demonstrate how to send email with direct SSL connection on 465 port.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"

using namespace System;
using namespace EASendMail;

int main(array<System::String ^> ^args)
{
    try
    {
        SmtpMail ^oMail = gcnew SmtpMail("TryIt");

        // Set sender email address, please change it to yours
        oMail->From = "test@emailarchitect.net";
        // Set recipient email address, please change it to yours
        oMail->To = gcnew AddressCollection("support@emailarchitect.net");

        // Set email subject
        oMail->Subject = "test email from Managed C++ project";
        // Set email body
        oMail->TextBody = "this is a test email sent from Managed C++ project, do not reply";

        // Your SMTP server address
        SmtpServer ^oServer = gcnew SmtpServer("smtp.emailarchitect.net");

        // User and password for ESMTP authentication
        oServer->User = "test@emailarchitect.net";
        oServer->Password = "testpassword";

        // Set SSL 465 port
        oServer->Port = 465;

        // Set direct SSL connection, you can also use ConnectSSLAuto
        oServer->ConnectType = SmtpConnectType::ConnectDirectSSL;

        Console::WriteLine("start to send email from Managed C++...");

        SmtpClient ^oSmtp = gcnew SmtpClient();
        oSmtp->SendMail(oServer, oMail);

        Console::WriteLine("email was sent successfully!");
    }
    catch (Exception ^ep)
    {
        Console::WriteLine("failed to send email with the following error:");
        Console::WriteLine(ep->Message);
    }

    return 0;
}

[Managed C++ Example - Send email over TLS on 25 or 587 port]¶

The following example codes demonstrate how to use EASendMail SMTP component to send email with TLS (STARTTLS command) connection on 25 port.

Note

To get the full sample projects, please refer to Samples section.

#include "stdafx.h"

using namespace System;
using namespace EASendMail;

int main(array<System::String ^> ^args)
{
    try
    {
        SmtpMail ^oMail = gcnew SmtpMail("TryIt");

        // Set sender email address, please change it to yours
        oMail->From = "test@emailarchitect.net";
        // Set recipient email address, please change it to yours
        oMail->To = gcnew AddressCollection("support@emailarchitect.net");

        // Set email subject
        oMail->Subject = "test email from Managed C++ project";
        // Set email body
        oMail->TextBody = "this is a test email sent from Managed C++ project, do not reply";

        // Your SMTP server address
        SmtpServer ^oServer = gcnew SmtpServer("smtp.emailarchitect.net");

        // User and password for ESMTP authentication
        oServer->User = "test@emailarchitect.net";
        oServer->Password = "testpassword";

        // Set 25 port or 587 port
        oServer->Port = 25;

        // detect TLS/SSL automatically, you can also use ConnectSSLAuto
        oServer->ConnectType = SmtpConnectType::ConnectSTARTTLS;

        Console::WriteLine("start to send email from Managed C++...");

        SmtpClient ^oSmtp = gcnew SmtpClient();
        oSmtp->SendMail(oServer, oMail);

        Console::WriteLine("email was sent successfully!");
    }
    catch (Exception ^ep)
    {
        Console::WriteLine("failed to send email with the following error:");
        Console::WriteLine(ep->Message);
    }

    return 0;
}

Next Section

At next section I will introduce how to send email using Gmail account.

Tutorial Index

Send Email over SSL/TLS in Managed C++/CLI¶

SSL and TLS Introduction¶

TLS 1.2¶

[Managed C++/CLI Exmaple - SSL/TLS]¶

[Managed C++ Example - Send email over direct SSL on 465 port]¶

[Managed C++ Example - Send email over TLS on 25 or 587 port]¶

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