Listen for Mail Change Notification Using Microsoft Graph API in C# ASP.NET Core

Question

Listen for Mail Change Notification Using Microsoft Graph API in C# ASP.NET Core

Sruthi Kurup 0

How do I develop an ASP.NET Core application that listens to change notification upon receiving a new mail based on some condition? I've already created a sample app by referring to this YouTube tutorial: https://www.youtube.com/watch?v=fThiCZmIcMQ&list=PLWZJrkeLOrbbOve1DVVQsauZX2LN3IEHL&index=12.

However, I'm encountering two challenges:

I need to get the user credentials (Client ID, Tenant ID, and Application Secret) through an API, then create a subscription for the particular user, and listen to the notification when a new mail arrives, and give the response back to the application user, who has the MS account linked with.
The user will input the credentials on a different organization.

What I have done so far:

Created an Office 365 account on trial.
Registered an app in Azure Portal (entraid) with which I set up my supported accounts to Multitenant.
Configured ngork and setup it to listen to my application port.
Created an ASP.NET Core 7 application and updated the AppSettings with accurate admin credentials (Tenant ID, Client ID, Client Secret, ngork URL, etc.).

I also referred to this GitHub page, but a lot of breaking changes are there in the Graph API, so it gets difficult to update to my application: https://github.com/microsoftgraph/aspnetcore-webhooks-sample

Please help me to handle challenge 1 and 2 and resolve the issue.

Sruthi Kurup 0 Reputation points

2024-01-03T11:10:39.52+00:00

i need to create and listen to all the subscriptions according to the account which the user give. the sample application https://github.com/microsoftgraph/aspnetcore-webhooks-sample this does similar to my requirement. but I don't need any additional certificates or interactive token mode to login creating the subscription. also the sample application have the demo of how can we use the teams chatmessage.

1 answer

Your answer

Sruthi Kurup 0 Reputation points

2024-01-03T11:10:39.52+00:00

i need to create and listen to all the subscriptions according to the account which the user give. the sample application https://github.com/microsoftgraph/aspnetcore-webhooks-sample this does similar to my requirement. but I don't need any additional certificates or interactive token mode to login creating the subscription. also the sample application have the demo of how can we use the teams chatmessage.

Answer 1

Sourabh Gupta 800 Microsoft External Staff

Hi Sruthi Kurup, Thanks for reaching out!

Could you please try use the following subscription object while creating the new subscription.

					DateTimeOffset expirationDateTime = DateTimeOffset.UtcNow.AddDays(2);

                    var Subscription = new Subscription
                    {
                        ChangeType = "created",
                        NotificationUrl = $"{notificationHost}/api/{endpoint where notification will come}/",
                        Resource = $"/users/{payload.UserId}//messages",
                        ExpirationDateTime = expirationDateTime,
                        ClientState = "my notification service",
                    };
                    var CreatedSubscription = await graphClient.Subscriptions.Request().AddAsync(Subscription);

Also, you need to renew this subscription every 2 days based upon what is the expiry time. Feel free to reply again in case you need more specific help.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment"

Sruthi Kurup 0

@Sourabh Gupta please review my code


[ApiController]
[Route("[controller]")]
public class GraphWatchController : ControllerBase
{
    private readonly ILogger<GraphWatchController> _logger;
    private readonly IConfiguration _configuration;

    public GraphWatchController(ILogger<GraphWatchController> logger,IConfiguration configuration)
    {
        _logger = logger;
        _configuration = configuration;
    }

    public IResult Get(string clientId, string clientSecret, string tenantId, string mailBox)
    {
        var graphClient = new GraphServiceClient(new ClientSecretCredential(
            tenantId, clientId, clientSecret));


        var sub = new Subscription
        {
            ChangeType = "created,updated",
            NotificationUrl = _configuration.Ngrok + "/api/graphlisten",
            LifecycleNotificationUrl = _configuration.Ngrok + "/api/graphlifecycle",
            Resource = $"/me/mailFolders('{mailBox}')/messages",
            ExpirationDateTime = DateTime.UtcNow.AddMinutes(15),
            ClientState = "SecretClientState"
        };

        var newSubscription = graphClient
            .Subscriptions.PostAsync(sub).Result;

        return Results.Ok($"Subscribed. Id: {newSubscription.Id}, Expiration: {newSubscription.ExpirationDateTime}");
    }
}

[ApiController]
[Route("[controller]")]
public class GraphListenController : ControllerBase
{
    private readonly ILogger<GraphListenController> _logger;

    public GraphListenController(ILogger<GraphListenController> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// POST /listen
    /// </summary>
    /// <param name="validationToken">Optional. Validation token sent by Microsoft Graph during endpoint validation phase</param>
    /// <returns>IActionResult</returns>
    [HttpPost]
    [AllowAnonymous]
    public async Task<IResult> Post([FromQuery] string? validationToken = null)
    {
        // If there is a validation token in the query string,
        // send it back in a 200 OK text/plain response
        if (!string.IsNullOrEmpty(validationToken))
        {
            return Results.Ok(validationToken);
        }

        // Use the Graph client's serializer to deserialize the body
        using var bodyStream = new MemoryStream();
        await Request.Body.CopyToAsync(bodyStream);
        bodyStream.Seek(0, SeekOrigin.Begin);
        var notifications = KiotaJsonSerializer.Deserialize<ChangeNotificationCollection>(bodyStream);

        if (notifications == null || notifications.Value == null) return Results.Accepted();

        // Validate any tokens in the payload
        var areTokensValid = await notifications.AreTokensValid(_tenantIds, _appIds);
        if (!areTokensValid) return Results.Unauthorized();

        // Process non-encrypted notifications first
        // These will be notifications for user mailbox
        var messageNotifications = new Dictionary<string, ChangeNotification>();
        foreach (var notification in notifications.Value.Where(n => n.EncryptedContent == null))
        {
            // Find the subscription in our store
            var subscription = _subscriptionStore
                .GetSubscriptionRecord(notification.SubscriptionId.ToString() ?? string.Empty);

            // If this isn't a subscription we know about, or if client state doesn't match,
            // ignore it
            if (subscription != null && subscription.ClientState == notification.ClientState)
            {
                _logger.LogInformation($"Received notification for: {notification.Resource}");
                // Add notification to list to process. If there is more than
                // one notification for a given resource, we'll only process it once
                messageNotifications[notification.Resource!] = notification;
            }
        }

        return Results.Accepted();
    }
}

[ApiController]
[Route("[controller]")]
public class GraphLifeCycleController : ControllerBase
{
    private readonly ILogger<GraphLifeCycleController> _logger;

    public GraphLifeCycleController(ILogger<GraphLifeCycleController> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// POST /lifecycle
    /// </summary>
    /// <param name="validationToken">Optional. Validation token sent by Microsoft Graph during endpoint validation phase</param>
    /// <returns>IActionResult</returns>
    [HttpPost]
    [AllowAnonymous]
    public async Task<IActionResult> Post([FromQuery] string? validationToken = null)
    {
        // If there is a validation token in the query string,
        // send it back in a 200 OK text/plain response
        if (!string.IsNullOrEmpty(validationToken))
        {
            return Ok(validationToken);
        }

        // Use the Graph client's serializer to deserialize the body
        using var bodyStream = new MemoryStream();
        await Request.Body.CopyToAsync(bodyStream);
        bodyStream.Seek(0, SeekOrigin.Begin);
        var notifications = KiotaJsonSerializer.Deserialize<ChangeNotificationCollection>(bodyStream);

        if (notifications == null || notifications.Value == null) return Accepted();

        // Process any lifecycle events
        var lifecycleNotifications = notifications.Value.Where(n => n.LifecycleEvent != null);
        foreach (var lifecycleNotification in lifecycleNotifications)
        {
            _logger.LogInformation("Received {eventType} notification for subscription {subscriptionId}",
                lifecycleNotification.LifecycleEvent.ToString(), lifecycleNotification.SubscriptionId);

            if (lifecycleNotification.LifecycleEvent == LifecycleEventType.ReauthorizationRequired)
            {
                // The subscription needs to be renewed
                try
                {
                    await RenewSubscriptionAsync(lifecycleNotification);
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, "Error renewing subscription");
                }
            }
        }

        // Return 202 to Graph to confirm receipt of notification.
        // Not sending this will cause Graph to retry the notification.
        return Accepted();
    }
}

this is the modification i've done to the code

in my application i have already created a login and logout mechanism which will work with the help of identity framework. and i'm saving the details in the db in the aspusers table. using jwt token login and logout session works.

so the user will login into the application using these credentials, and after login the user can create subscription for an account the user wishes to. like wise single user in application can create multiple subscriptions using multiple accounts.

in this case, like the modification to the subscription api, i can get the desired user credentials and create subscription. but i'm not sure how to listen to the mailbox for the subscribed events. i've done according to what do in a console app, not similar to what we do in a asp.net core application. please help me to complete the apis properly in asp.net core

Sruthi Kurup 0 Reputation points

2024-01-08T08:06:55.6433333+00:00

i've tried to contact andrew connell and this was his reply, the link he's saying in the reply is not much helpful, this redirects to Microsoft graph sdk documentation. not have documentation of how can do when a single user have to use multiple accounts inside to create the subscription and listen only.

Sourabh Gupta 800 Microsoft External Staff

Hi Sruthi Kurup You are using client secret authentication and this is meant for application level access

For using the me endpoint in Resource ( which corresponds to current logged in user) you need to use pass user authentication token so that Graph can identify for which user.

You can use some code like this to get token on behalf of the user and then create Graph service client object.

private async Task<string> GetAccessToken()
        {
            IConfidentialClientApplication app = ConfidentialClientApplicationBuilder.Create(APP_ID)
              .WithClientSecret(APP_SECRET)
              .WithAuthority($"https://login.microsoftonline.com/{TENANT_ID}")
              .WithRedirectUri("https://localhost")
              .Build();

            string[] scopes = new string[] { "https://graph.microsoft.com/.default" };

            var result = await app.AcquireTokenForClient(scopes).ExecuteAsync();

            return result.AccessToken;
        }

private GraphServiceClient GetGraphClient()
        {
            var graphClient = new GraphServiceClient(new DelegateAuthenticationProvider((requestMessage) => {
                // get an access token for Graph
                var accessToken = GetAccessToken().Result;

                requestMessage
                    .Headers
                    .Authorization = new AuthenticationHeaderValue("bearer", accessToken);

                return Task.FromResult(0);
            }));

            return graphClient;
        }

Sruthi Kurup 0 Reputation points

2024-01-09T08:03:39.6333333+00:00

yes, @Sourabh Gupta how will i create a listen webhook in this case?
Sruthi Kurup 0 Reputation points

2024-01-09T08:05:25.35+00:00

yes @Sourabh Gupta how will i create a listen webhook, if i do subscription like this?
Sourabh Gupta 800 Reputation points Microsoft External Staff

2024-01-13T13:02:23.29+00:00

Hi @Sruthi Kurup The listen webhook can either be an Azure function or an endpoint where the post request from Microsoft will hit and you just have to read the request body and process it, You also need to write down a code to validate the token send when subscription is created, Do let me know if you need a sample code
Sruthi Kurup 0 Reputation points

2024-01-17T09:54:44.27+00:00

@Sourabh Gupta could you please provide the sample code, so that i can work on it?

Sourabh Gupta 800 Microsoft External Staff

Hi Sruthi,

Thanks for the wait.

You can use the following code for your notification listener end point. This code is reading notification data from the notification request body.

Firstly, it is looking for the validation token, by which it verifies whether the endpoint mentioned while creating subscriptions is valid or not.

Thereafter when notification comes up, we need to read body of request to fetch notification object to process the notification.

All the notification requests are being raised from Ip addresses mentioned on the link below on row no 23. These ips needs to be whitelisted on your firewall.

Other endpoints not included in the Office 365 IP Address and URL Web service - Microsoft 365 Enterprise | Microsoft Learn

When you have notification end point running on local host you need to use some proxy tool like ng rok, in order to simulate the urls.

//Checking if this is a validation request?
                string validationToken = req.Query["validationToken"];
                if (!string.IsNullOrEmpty(validationToken))
                {
                    return new OkObjectResult(validationToken);
                }
                var requestBody = await new StreamReader(req.Body).ReadToEndAsync();
                var jsonOptions = new JsonSerializerOptions
                {
                    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
                };
                var notifications = System.Text.Json.JsonSerializer.Deserialize<NotificationList>(requestBody, jsonOptions);
                foreach (var notification in notifications.Value)
                {
                    if (notification.ClientState == ClientState)
                    {
                        // Process each notification
                        await ProcessNotification(notification);
                    }
                    else
                    {
                        log.LogInformation($"Notification received with unexpected client state: {notification.ClientState}");
                    }
                }
                return new AcceptedResult()

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Listen for Mail Change Notification Using Microsoft Graph API in C# ASP.NET Core

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