SMTP protocol from Office 365 in background service¶

You can send email using traditional user/password authentication from Office 365 account by EWS/Ms Graph API Protocol.

However Microsoft has disabled traditional user authentication in many tenants, switching to Microsoft OAuth (Modern Authentication) is strongly recommended now.

In this topic, I will introduce how to send email using C++/CLI and Microsoft OAuth (Modern Authentication) in background service.

Sections:

Installation
Add reference
.NET assembly
Office 365 OAuth 2.0 client credentials grant
Register the application in Azure Portal
Register application
Find the application id (client id) and tenant id
Assign API permission
Graph API permission
Add Mail.Send and Mail.ReadWrite permission
EWS and SMTP/POP/IMAP permission
Add full_access_app permission
Add POP.AccessAsApp permission
Add IMAP.AccessAsApp permission
Add SMTP.AccessAsApp permission
Complete permissions list
Grant admin consent in API permission
Create client secret
Store client secret value
Enable TLS Strong Encryption Algorithms in .NET 2.0 and .NET 4.0
Managed C++/CLI - Send email using Ms Graph API + Microsoft OAuth from Office 365 account in background service - example
Managed C++/CLI - Send email using EWS + Microsoft OAuth from Office 365 account in background service - example
Register SMTP/POP/IMAP service principals in Exchange
Find APPLICATION_ID and OBJECT_ID
Open Exchange Online PowerShell
Create service principal
Query service principal
Add permission to specific user
Query permission
Managed C++/CLI - Send email using SMTP + Microsoft OAuth from Office 365 account in background service - example
Access token lifetime
TLS 1.2 protocol
EA Oauth Service for Office 365
Related links

Installation¶

Before you can use the following codes, please download EASendMail SMTP Component and install it on your machine at first. Full sample proejcts are included in this installer.

Install from NuGet

You can also install the run-time assembly by NuGet. Run the following command in the NuGet Package Manager Console:

Install-Package EASendMail

Note

If you install it by NuGet, no sample projects are installed, only .NET assembly is installed.

Add reference¶

To use EASendMail SMTP Component in your project, the first step is Add reference of EASendMail to your project. Please create or open your project with Visual Studio, then go to menu -> Project -> Add Reference -> .NET -> Browse..., and select Installation Path\Lib\net[version]\EASendMail.dll from your disk, click Open -> OK, the reference of EASendMail will be added to your project, and you can start to use it to send email in your project.

.NET assembly¶

Because EASendMail has separate builds for .Net Framework, please refer to the following table and choose the correct dll.

Separate builds of run-time assembly for .NET Framework 2.0, 3.5, 4.0, 4.5, 4.6.1, 4.7.2, 4.8.1, .NET 5.0, .NET 6.0, .NET 7.0, .NET 8.0, .NET Standard 2.0 and .NET Compact Framework 2.0, 3.5.

File	.NET Framework Version
Lib\[net20\|40\|45\|461\|472\|481]\EASendMail.dll	Built with .NET Framework 2.0, 4.0, 4.5, 4.6.1, 4.7.2, 4.8.1 It requires .NET Framework 2.0, 3.5 or later version.
Lib\[net5.0\|6.0\|7.0\|8.0]\EASendMail.dll	Built with .NET 5.0, .NET 6.0, .NET 7.0, .NET 8.0 It requires .NET 5.0 or later version.
Lib\netstandard2.0\EASendMail.dll	Built with .NET Standard 2.0 It requires .NET Standard 2.0 or later version.
Lib\[net20-cf\|net35-cf]\EASendMail.dll	Built with .NET Compact Framework 2.0, 3.5 It requires .NET Compact Framework 2.0, 3.5 or later version.

Office 365 OAuth 2.0 client credentials grant¶

Normal OAuth requires user to input user and password in browser for authentication. Obviously, it is not suitable for background service.

The solution is granting admin consent to the azure application, then the application can use the client secret value to request the access token directly. This way doesn’t require user attending, it is suitable for background service.

This tutorial introduces how to register application for background service in Azure Portal, then assign the Graph API/EWS/SMTP/POP/IMAP API permission to the application and add the access right to the mailbox of specific user.

Register the application in Azure Portal¶

Sign in to the Azure Portal using the Microsoft account of the Office 365 administrator. If your account gives you access to more than one tenant, select your account in the top right corner, and set your portal session to the Azure AD tenant that you want.

Search Microsoft Entra ID (old name “Azure Active Directory”) and go to this service:

Register application¶

In the left-hand navigation pane, select the Microsoft Entra ID service, and then select -> Manage -> App registrations -> New registration.

Input a name to to register the application:

Find the application id (client id) and tenant id¶

After the application is registered, you can click Overview to find the client id and tenant id. These are required parameters for requesting access token.

Assign API permission¶

Now you need to assign API permission to the application by clicking Manage -> API Permission -> Add a permission.

You don’t have to assign all the API permissions below to the application, just assign the API permission(s) you need.

Protocol	Permission	Scope
Graph API	Mail.Send, Mail.ReadWrite	https://graph.microsoft.com/.default
EWS	full_access_as_app	https://outlook.office365.com/.default
SMTP	SMTP.AccessAsApp	https://outlook.office365.com/.default
POP	POP.AccessAsApp	https://outlook.office365.com/.default
IMAP	IMAP.AccessAsApp	https://outlook.office365.com/.default

Graph API permission¶

Go to Microsoft APIs -> Microsoft Graph -> Application Permission ->

Add Mail.Send and Mail.ReadWrite permission¶

add Graph Mail.Send Mail.ReadWrite permission to app in azure

EWS and SMTP/POP/IMAP permission¶

Go to APIs in my organization uses -> Office 365 Exchange Online -> Application Permission ->

add exchange online permission to app in azure

Add full_access_app permission¶

add exchange online EWS permission to app in azure

Add POP.AccessAsApp permission¶

add exchange online POP permission to app in azure

Add IMAP.AccessAsApp permission¶

add exchange online IMAP permission to app in azure

Add SMTP.AccessAsApp permission¶

add exchange online SMTP permission to app in azure

Complete permissions list¶

Create client secret¶

Now we need to create a client secret for the application, click Certificates and secrets -> client secrets and add a new client secret.

Store client secret value¶

After client secret is created, store the client secret value to somewhere. It is another required parameter for requesting access token.

Important

Please store client secret value by yourself, because it is hidden when you view it at next time.

Now you can use the client id, tenant id and client secret value to request access token. But to use SMTP/POP/IMAP protocol, you need to Register SMTP/POP/IMAP service principals in Exchange as well.

Important

You should create your client id and client secret, do not use the client id from example codes in production environment, it is used for test purpose. If you got "This app isn't verified" information, please click "Advanced" -> Go to ... for test.

Enable TLS Strong Encryption Algorithms in .NET 2.0 and .NET 4.0¶

Because HttpWebRequest is used to get access token from web service. If you’re using .NET framework (.NET 2.0 - 3.5 and .NET 4.x), you need to enable Strong Encryption Algorithms to request access token:

Put the following content to a file named NetStrongEncrypt.reg, right-click this file -> Merge -> Yes. You can also download it from https://www.emailarchitect.net/webapp/download/NetStrongEncrypt.zip.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v2.0.50727]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

Now you can use the following example codes to send email with Graph API or EWS protocol:

Managed C++/CLI - Send email using Ms Graph API + Microsoft OAuth from Office 365 account in background service - example¶

#include "stdafx.h"

using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
using namespace System::Threading;
using namespace System::Threading::Tasks;
using namespace System::Runtime::InteropServices;
using namespace EASendMail;

static String^ _postString(String^ uri, String^ requestData)
{
    HttpWebRequest^ httpRequest = (HttpWebRequest^)WebRequest::Create(uri);
    httpRequest->Method = "POST";
    httpRequest->ContentType = "application/x-www-form-urlencoded";

    Stream ^requestStream = httpRequest->GetRequestStream();
    auto requestBuffer = Encoding::UTF8->GetBytes(requestData);
    requestStream->Write(requestBuffer, 0, requestBuffer->Length);
    requestStream->Close();

    try
    {
        HttpWebResponse^ httpResponse = (HttpWebResponse^)httpRequest->GetResponse();
        StreamReader^ reader = gcnew StreamReader(httpResponse->GetResponseStream());
        {
            // reads response body
            String^ responseText = reader->ReadToEnd();
            Console::WriteLine(responseText);
            return responseText;
        }
    }
    catch (WebException ^ex)
    {
        if (ex->Status == WebExceptionStatus::ProtocolError)
        {
            auto response = (HttpWebResponse^)ex->Response;
            if (response != nullptr)
            {
                Console::WriteLine("HTTP: " + response->StatusCode.ToString());
                StreamReader ^reader = gcnew StreamReader(response->GetResponseStream());
                {
                    // reads response body
                    String^ responseText = reader->ReadToEnd();
                    Console::WriteLine(responseText);
                }
            }
        }

        throw ex;
    }
}

static void SendMail()
{
    try
    {
        String^ client_id = "b22194da-44d6-4320-a067-e86a275d6fa4";
        String^ client_secret = "VTO8Q~eo0JCXc291jcM4wnhZ_GXyKMu.";

        // If your application is not created by Office365 administrator,
        // please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        // Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        String^ tenant = "2ea4955d-830e-4aa7-8ab5-661a6b9aa84d";

        String^ requestData =
            String::Format("client_id={0}&client_secret={1}&scope=https://graph.microsoft.com/.default&grant_type=client_credentials",
                client_id, client_secret);

        String^ tokenUri = String::Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant);
        String^ responseText = _postString(tokenUri, requestData);

        OAuthResponseParser^ parser = gcnew OAuthResponseParser();
        parser->Load(responseText);

        String^ officeUser = "user@mydomain.onmicrosoft.com";

        // Set Ms Graph API server address and protocol
        auto server = gcnew SmtpServer("graph.microsoft.com");
        server->Protocol = ServerProtocol::MsGraphApi;

        server->User = officeUser;
        server->Password = parser->AccessToken;
        server->AuthType = SmtpAuthType::XOAUTH2;

        server->ConnectType = SmtpConnectType::ConnectSSLAuto;

        auto mail = gcnew SmtpMail("TryIt");

        mail->From = officeUser;
        mail->To = "support@emailarchitect.net";

        mail->Subject = "Office 365 background service oauth test";
        mail->TextBody = "this is a test, don't reply";

        auto smtp = gcnew SmtpClient();
        smtp->SendMail(server, mail);

        Console::WriteLine("Message delivered!");
    }
    catch (Exception^ ep)
    {
        Console::WriteLine(ep->ToString());
    }
}

Managed C++/CLI - Send email using EWS + Microsoft OAuth from Office 365 account in background service - example¶

#include "stdafx.h"

using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
using namespace System::Threading;
using namespace System::Threading::Tasks;
using namespace System::Runtime::InteropServices;
using namespace EASendMail;

static String^ _postString(String^ uri, String^ requestData)
{
    HttpWebRequest^ httpRequest = (HttpWebRequest^)WebRequest::Create(uri);
    httpRequest->Method = "POST";
    httpRequest->ContentType = "application/x-www-form-urlencoded";

    Stream ^requestStream = httpRequest->GetRequestStream();
    auto requestBuffer = Encoding::UTF8->GetBytes(requestData);
    requestStream->Write(requestBuffer, 0, requestBuffer->Length);
    requestStream->Close();

    try
    {
        HttpWebResponse^ httpResponse = (HttpWebResponse^)httpRequest->GetResponse();
        StreamReader^ reader = gcnew StreamReader(httpResponse->GetResponseStream());
        {
            // reads response body
            String^ responseText = reader->ReadToEnd();
            Console::WriteLine(responseText);
            return responseText;
        }
    }
    catch (WebException ^ex)
    {
        if (ex->Status == WebExceptionStatus::ProtocolError)
        {
            auto response = (HttpWebResponse^)ex->Response;
            if (response != nullptr)
            {
                Console::WriteLine("HTTP: " + response->StatusCode.ToString());
                StreamReader ^reader = gcnew StreamReader(response->GetResponseStream());
                {
                    // reads response body
                    String^ responseText = reader->ReadToEnd();
                    Console::WriteLine(responseText);
                }
            }
        }

        throw ex;
    }
}

static void SendMail()
{
    try
    {
        String^ client_id = "b22194da-44d6-4320-a067-e86a275d6fa4";
        String^ client_secret = "VTO8Q~eo0JCXc291jcM4wnhZ_GXyKMu.";

        // If your application is not created by Office365 administrator,
        // please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        // Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        String^ tenant = "2ea4955d-830e-4aa7-8ab5-661a6b9aa84d";

        String^ requestData =
            String::Format("client_id={0}&client_secret={1}&scope=https://outlook.office365.com/.default&grant_type=client_credentials",
                client_id, client_secret);

        String^ tokenUri = String::Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant);
        String^ responseText = _postString(tokenUri, requestData);

        OAuthResponseParser^ parser = gcnew OAuthResponseParser();
        parser->Load(responseText);

        String^ officeUser = "user@mydomain.onmicrosoft.com";
        auto server = gcnew SmtpServer("outlook.office365.com");
        server->Protocol = ServerProtocol::ExchangeEWS;
        server->User = officeUser;

        server->Password = parser->AccessToken;
        server->AuthType = SmtpAuthType::XOAUTH2;
        server->ConnectType = SmtpConnectType::ConnectSSLAuto;

        auto mail = gcnew SmtpMail("TryIt");

        mail->From = officeUser;
        mail->To = "support@emailarchitect.net";

        mail->Subject = "Office 365 background service oauth test";
        mail->TextBody = "this is a test, don't reply";

        auto smtp = gcnew SmtpClient();
        smtp->SendMail(server, mail);

        Console::WriteLine("Message delivered!");
    }
    catch (Exception^ ep)
    {
        Console::WriteLine(ep->ToString());
    }
}

Register SMTP/POP/IMAP service principals in Exchange¶

Although the application is consented by the tenant admin, but to access SMTP/POP/IMAP service, the tenant administrator still need to register your application as service principal in Exchange via Exchange Online PowerShell. This is enabled by the New-ServicePrincipal cmdlet.

New-ServicePrincipal -AppId <APPLICATION_ID> -ServiceId <OBJECT_ID>

Find APPLICATION_ID and OBJECT_ID¶

You should find your APPLICATION_ID and OBJECT_ID before running above cmdlet. Go to Overview -> Managed application in local directory:

After you click your application name in Managed application in l..., you can see Application ID and Object ID for New-ServicePrincipal cmdlet.

find object id in Managed application in local directory

Open Exchange Online PowerShell¶

Now you need to open Exchange Online PowerShell to run the cmdlet. If you have not installed the module, you can use the Install-Module cmdlet to install the module from the PowerShell Gallery.

Install-Module -Name ExchangeOnlineManagement

After you’ve installed the module, open a PowerShell window and load the module by running the following command:

Import-Module ExchangeOnlineManagement

Connect-ExchangeOnline -UserPrincipalName "admin@yourdomain.onmicrosoft.com"

Create service principal¶

After Exchange Online PowerShell is connected successfully, run the following cmdlet to create a new service principal: The ServiceId is the OBJECT_ID and the AppId is APPLICATION_ID found in Find APPLICATION_ID and OBJECT_ID

New-ServicePrincipal -AppId "b22194da-44d6-4320-a067-e86a275d6fa4" -ServiceId "71941e67-ef24-45e8-bd22-dfd53790bb77"

Query service principal¶

After you create the service principal, you can query it by:

Get-ServicePrincipal

Add permission to specific user¶

You can now add the specific mailboxes in the tenant that will be allowed to be access by your application. This is done with the Add-MailboxPermission cmdlet.

Add-MailboxPermission -Identity <mailboxIdParameter> -User <SecurityPrincipalIdParameter|OBJECT_ID>  -AccessRights <MailboxRights[]>

For example:

Add-MailboxPermission -Identity "grant-test@emailarchitect.net" -User "71941e67-ef24-45e8-bd22-dfd53790bb77" -AccessRights FullAccess

Query permission¶

You can also query the permission by:

Get-MailboxPermission -Identity "grant-test@emailarchitect.net"

Now you can use SMTP protocol to send email by the following codes:

Managed C++/CLI - Send email using SMTP + Microsoft OAuth from Office 365 account in background service - example¶

#include "stdafx.h"

using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
using namespace System::Threading;
using namespace System::Threading::Tasks;
using namespace System::Runtime::InteropServices;
using namespace EASendMail;

static String^ _postString(String^ uri, String^ requestData)
{
    HttpWebRequest^ httpRequest = (HttpWebRequest^)WebRequest::Create(uri);
    httpRequest->Method = "POST";
    httpRequest->ContentType = "application/x-www-form-urlencoded";

    Stream ^requestStream = httpRequest->GetRequestStream();
    auto requestBuffer = Encoding::UTF8->GetBytes(requestData);
    requestStream->Write(requestBuffer, 0, requestBuffer->Length);
    requestStream->Close();

    try
    {
        HttpWebResponse^ httpResponse = (HttpWebResponse^)httpRequest->GetResponse();
        StreamReader^ reader = gcnew StreamReader(httpResponse->GetResponseStream());
        {
            // reads response body
            String^ responseText = reader->ReadToEnd();
            Console::WriteLine(responseText);
            return responseText;
        }
    }
    catch (WebException ^ex)
    {
        if (ex->Status == WebExceptionStatus::ProtocolError)
        {
            auto response = (HttpWebResponse^)ex->Response;
            if (response != nullptr)
            {
                Console::WriteLine("HTTP: " + response->StatusCode.ToString());
                StreamReader ^reader = gcnew StreamReader(response->GetResponseStream());
                {
                    // reads response body
                    String^ responseText = reader->ReadToEnd();
                    Console::WriteLine(responseText);
                }
            }
        }

        throw ex;
    }
}

static void SendMail()
{
    try
    {
        String^ client_id = "b22194da-44d6-4320-a067-e86a275d6fa4";
        String^ client_secret = "VTO8Q~eo0JCXc291jcM4wnhZ_GXyKMu.";

        // If your application is not created by Office365 administrator,
        // please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        // Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        String^ tenant = "2ea4955d-830e-4aa7-8ab5-661a6b9aa84d";

        String^ requestData =
            String::Format("client_id={0}&client_secret={1}&scope=https://outlook.office365.com/.default&grant_type=client_credentials",
                client_id, client_secret);

        String^ tokenUri = String::Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant);
        String^ responseText = _postString(tokenUri, requestData);

        OAuthResponseParser^ parser = gcnew OAuthResponseParser();
        parser->Load(responseText);

        String^ officeUser = "grant-test@emailarchitect.net";
        auto server = gcnew SmtpServer("outlook.office365.com");
        server->Protocol = ServerProtocol::SMTP;
        server->Port = 587;

        server->User = officeUser;
        server->Password = parser->AccessToken;
        server->AuthType = SmtpAuthType::XOAUTH2;

        server->ConnectType = SmtpConnectType::ConnectSSLAuto;

        auto mail = gcnew SmtpMail("TryIt");

        mail->From = officeUser;
        mail->To = "support@emailarchitect.net";

        mail->Subject = "Office 365 background service oauth test";
        mail->TextBody = "this is a test, don't reply";

        auto smtp = gcnew SmtpClient();
        smtp->SendMail(server, mail);

        Console::WriteLine("Message delivered!");
    }
    catch (Exception^ ep)
    {
        Console::WriteLine(ep->ToString());
    }
}

Access token lifetime¶

You don’t have to request access token every time. By default, access token expiration time is 3600 seconds, you can reuse the access token repeatedly before it is expired.

TLS 1.2 protocol¶

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, 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

EA Oauth Service for Office 365¶

If you are not the tenant administrator and you don’t have the permission to create or grant the application in Azure, or if your code is too complex or out of maintenance, and you don’t want to change anything in your source codes, then you can have a try with EA Oauth Service for Offic365. It provides an easy way for the legacy email application that doesn’t support OAUTH 2.0 to send and retrieve email from Office 365 without changing any codes. SMTP, POP, IMAP and SSL/TLS protocols are supported.

Tutorial Index

Managed C++/CLI - Send email using Microsoft OAuth 2.0 (Modern Authentication) + EWS/Ms Graph API/SMTP protocol from Office 365 in background service¶

Installation¶

Add reference¶

.NET assembly¶

Office 365 OAuth 2.0 client credentials grant¶

Register the application in Azure Portal¶

Register application¶

Find the application id (client id) and tenant id¶

Assign API permission¶

Graph API permission¶

Add Mail.Send and Mail.ReadWrite permission¶

EWS and SMTP/POP/IMAP permission¶

Add full_access_app permission¶

Add POP.AccessAsApp permission¶

Add IMAP.AccessAsApp permission¶

Add SMTP.AccessAsApp permission¶

Complete permissions list¶

Create client secret¶

Store client secret value¶

Enable TLS Strong Encryption Algorithms in .NET 2.0 and .NET 4.0¶

Managed C++/CLI - Send email using Ms Graph API + Microsoft OAuth from Office 365 account in background service - example¶

Managed C++/CLI - Send email using EWS + Microsoft OAuth from Office 365 account in background service - example¶

Register SMTP/POP/IMAP service principals in Exchange¶

Find APPLICATION_ID and OBJECT_ID¶

Open Exchange Online PowerShell¶

Create service principal¶

Query service principal¶

Add permission to specific user¶

Query permission¶

Managed C++/CLI - Send email using SMTP + Microsoft OAuth from Office 365 account in background service - example¶

Access token lifetime¶

TLS 1.2 protocol¶

EA Oauth Service for Office 365¶

Share

See Also

Tutorial Index

Managed C++/CLI - Send email using Microsoft OAuth 2.0 (Modern Authentication) + EWS/Ms Graph API/SMTP protocol from Office 365 in background service¶

Installation¶

Add reference¶

.NET assembly¶

Office 365 OAuth 2.0 client credentials grant¶

Register the application in Azure Portal¶

Register application¶

Find the application id (client id) and tenant id¶

Assign API permission¶

Graph API permission¶

Add Mail.Send and Mail.ReadWrite permission¶

EWS and SMTP/POP/IMAP permission¶

Add full_access_app permission¶

Add POP.AccessAsApp permission¶

Add IMAP.AccessAsApp permission¶

Add SMTP.AccessAsApp permission¶

Complete permissions list¶

Grant admin consent in API permission¶

Create client secret¶

Store client secret value¶

Enable TLS Strong Encryption Algorithms in .NET 2.0 and .NET 4.0¶

Managed C++/CLI - Send email using Ms Graph API + Microsoft OAuth from Office 365 account in background service - example¶

Managed C++/CLI - Send email using EWS + Microsoft OAuth from Office 365 account in background service - example¶

Register SMTP/POP/IMAP service principals in Exchange¶

Find APPLICATION_ID and OBJECT_ID¶

Open Exchange Online PowerShell¶

Create service principal¶

Query service principal¶

Add permission to specific user¶

Query permission¶

Managed C++/CLI - Send email using SMTP + Microsoft OAuth from Office 365 account in background service - example¶

Access token lifetime¶

TLS 1.2 protocol¶

EA Oauth Service for Office 365¶

Related links¶

Share

See Also