C# Code to Read Office 365 Emails.

Hello Floyd Gladden,

As per our discussion, your domain currently has only one user (your personal account as a guest user). To successfully retrieve Office 365 emails using Microsoft Graph API, you need to follow below steps:

• Create new users within your domain in Azure Active Directory (AAD).
• Assign Office 365 licenses to those users.
• Once the licenses are assigned, you should be able to send and retrieve emails via Microsoft Graph API.

In my case, I have one user with active Office 365 E5 license assigned as below:

Now, I registered one application and granted both User.Read.All and Mail.Read permission of Application type like this:

When I ran below C# code, I got the mails of user successfully like this:

using Azure.Identity;

using Microsoft.Graph;

using Microsoft.Graph.Models;

class Program

{

    static async Task Main(string[] args)

    {

        string tenantId = "tenantId";

        string clientId = "appId";

        string clientSecret = "secret";

        string userId = "******@xxxxxxxx.onmicrosoft.com";

        try

        {

            var clientSecretCredential = new ClientSecretCredential(tenantId, clientId, clientSecret);

            var graphClient = new GraphServiceClient(clientSecretCredential);

            Console.WriteLine("Fetching emails...");

            var messages = await graphClient.Users[userId].Messages

                .GetAsync(requestConfiguration =>

                {

                    requestConfiguration.QueryParameters.Top = 10;

                    requestConfiguration.QueryParameters.Select = new string[] { "receivedDateTime", "subject", "from" };

                    requestConfiguration.QueryParameters.Orderby = new string[] { "receivedDateTime DESC" };

                });

            if (messages?.Value != null && messages.Value.Count > 0)

            {

                Console.WriteLine("Emails retrieved successfully:\n");

                foreach (var message in messages.Value)

                {

                    Console.WriteLine($"Received: {message.ReceivedDateTime}");

                    Console.WriteLine($"From: {message.From?.EmailAddress?.Address}");

                    Console.WriteLine($"Subject: {message.Subject}");

                    Console.WriteLine("---------------------------------------------------");

                }

            }

            else

            {

                Console.WriteLine("No emails found.");

            }

        }

        catch (Exception ex)

        {

            Console.WriteLine($"Error retrieving emails: {ex.Message}");

        }

    }

}

Response:

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