Send Email using Gmail in Managed C++/CLI

In previous section, I introduced how to send email over SSL connection. In this section, I will introduce how to use your Gmail account to send email in Managed C++.

Introduction

Gmail SMTP server address is smtp.gmail.com. It requires implicit SSL or explicit SSL (TLS) connection, and you should use your Gmail email address as the user name for ESMTP authentication.

Server Port SSL/TLS
smtp.gmail.com 25, 587 TLS
smtp.gmail.com 465 SSL

Gmail App Password

To help keep your account secure, starting May 30, 2022, ​​Google will no longer support the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password.

Therefore, you should sign in using App Passwords. An App Password is a 16-digit passcode that gives a less secure app or device permission to access your Google Account. App Passwords can only be used with accounts that have 2-Step Verification turned on. You need to use App Password instead of the user password for user authentication.

Another solution is Gmail OAUH, please see Gmail SMTP OAUTH section.

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.

[C++/CLI Example - Send email using Gmail account over SSL connection on 465 port]

The following example codes demonstrate how to send email using Gmail account.

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");

        // Your Gmail email address
        oMail->From = "gmailid@gmail.com";
        // 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++ with Gmail account";
        // Set email body
        oMail->TextBody = "this is a test email sent from Managed C++ project with gmail";

        // Gmail SMTP server address
        SmtpServer ^oServer = gcnew SmtpServer("smtp.gmail.com");
        // Gmail user authentication
        // For example: your email is "gmailid@gmail.com", then the user should be "gmailid@gmail.com"
        oServer->User = "gmailid@gmail.com";

        // Create app password in Google account
        // https://support.google.com/accounts/answer/185833?hl=en
        oServer->Password = "your app password";

        // Use 465 port
        oServer->Port = 465;

        // detect SSL/TLS automatically
        oServer->ConnectType = SmtpConnectType::ConnectSSLAuto;

        Console::WriteLine("start to send email with SSL connection...");

        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 using Gmail account over TLS connection on 587 port]

The following example codes demonstrate how to use EASendMail SMTP component to send email using Gmail account.

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");

        // Your Gmail email address
        oMail->From = "gmailid@gmail.com";
        // 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++ with Gmail account";
        // Set email body
        oMail->TextBody = "this is a test email sent from Managed C++ project with gmail";

        // Gmail SMTP server address
        SmtpServer ^oServer = gcnew SmtpServer("smtp.gmail.com");
        // Gmail user authentication
        // For example: your email is "gmailid@gmail.com", then the user should be "gmailid@gmail.com"
        oServer->User = "gmailid@gmail.com";

        // Create app password in Google account
        // https://support.google.com/accounts/answer/185833?hl=en
        oServer->Password = "your app password";

        // Use 587 port
        oServer->Port = 587;

        // detect SSL/TLS automatically
        oServer->ConnectType = SmtpConnectType::ConnectSSLAuto;

        Console::WriteLine("start to send email with SSL connection...");

        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;
}

Gmail SMTP OAUTH

The Gmail IMAP and SMTP servers have been extended to support authorization via the industry-standard OAuth 2.0 protocol. Using OAUTH protocol, user can do authentication by Gmail Web OAuth instead of inputting user and password directly in application.

Google will disable traditional user authentication in the future, switching to Google OAuth is strongly recommended now.

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

Next Section

At next section I will introduce how to send email with Yahoo account.

Appendix

Comments

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