How can i export contacts from public folder?

Hi Michael_Kolowicz,

To export contacts from a public folder in Office 365 to a CSV file using a .NET Core application, you should utilize the Microsoft Graph API. This API is the recommended and modern way to programmatically access Office 365 data, including public folders.

Here are the key steps to accomplish this task:

1. Application Registration:

   • Start by registering your application in Azure AD. This registration process will involve specifying the required permissions to access the public folder. Ensure you grant the appropriate permissions based on your needs.

2. Authentication:

   • Employ a library like the Microsoft Authentication Library (MSAL) for .NET Core to manage the authentication process. This will allow you to obtain an access token using your application's credentials.

3. Access the Public Folder:

   • Utilize the Microsoft Graph API, specifically the Outlook API, to access the contacts within the public folder. This API allows you to interact with the contacts stored there.

4. Export Contacts to CSV:

   • Retrieve the contacts from the public folder and format the data for export to a CSV file. You can make use of the standard System.IO namespace in .NET Core to create and write data to a CSV file.

5. Scheduling:

   • To run your application at regular intervals, consider using a scheduling mechanism like the Windows Task Scheduler or implement recurring jobs using a library like Hangfire.

Here's a simplified example in .NET Core (C#) demonstrating how to access contacts in a public folder using the Microsoft Graph API:

using Microsoft.Graph;
using Microsoft.Identity.Client;

// Authentication
var clientId = "YOUR_CLIENT_ID";
var clientSecret = "YOUR_CLIENT_SECRET";
var tenantId = "YOUR_TENANT_ID";
var authority = $"https://login.microsoftonline.com/{tenantId}";
var scopes = new string[] { "https://graph.microsoft.com/.default" };

var app = PublicClientApplicationBuilder.Create(clientId)
    .WithAuthority(authority)
    .WithRedirectUri("http://localhost") // Redirect URI for console apps
    .Build();

var result = app.AcquireTokenForClient(scopes).ExecuteAsync().GetAwaiter().GetResult();
var accessToken = result.AccessToken;

// Initialize the GraphServiceClient
var graphClient = new GraphServiceClient(new DelegateAuthenticationProvider((requestMessage) =>
{
    requestMessage.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
    return Task.CompletedTask;
}));

// Access the public folder's contacts
var contacts = await graphClient.Users["publicFolderMailboxId"].Contacts.Request().GetAsync();

// Export contacts to CSV
foreach (var contact in contacts)
{
    // Write contact data to CSV file
}

// Implement the scheduling mechanism to run this code periodically.