How can I delete non-mail items from the 'Deleted Items' folder using Microsoft Graph API?

Note that, you can only delete email messages in the "Deleted Items" folder using Graph API. Currently, retrieving or deleting non-mail items like calendar events, tasks, contacts, etc. via Microsoft Graph API is not supported .

To get all the email messages present in "Deleted Items" folder, you can run below API call:

HTTPCopied
GET https://graph.microsoft.com/v1.0/me/mailFolders/deleteditems/messages?$count=true

Response:

In my case, I ran below c# code that uses interactive flow to connect with Microsoft Graph for deleting email messages present in "Deleted Items" folder programmatically:

CSHARPCopied
using Azure.Identity;
using Microsoft.Graph;
using Microsoft.Graph.Models.ODataErrors;

class Program
{
    static async Task Main(string[] args)
    {
        var tenantId = "tenantId";
        var clientId = "appId";
        var scopes = new[] { "https://graph.microsoft.com/Mail.ReadWrite" };

        var interactiveCredential = new InteractiveBrowserCredential(new InteractiveBrowserCredentialOptions
        {
            TenantId = tenantId,
            ClientId = clientId,
            AuthorityHost = AzureAuthorityHosts.AzurePublicCloud,
            RedirectUri = new Uri("http://localhost")
        });

        var graphClient = new GraphServiceClient(interactiveCredential, scopes);

        try
        {
            var messageIds = await GetDeletedItemsMessages(graphClient);

            if (messageIds.Count > 0)
            {
                await DeleteMessages(graphClient, messageIds);
                Console.WriteLine("All messages deleted from Deleted Items.");
            }
            else
            {
                Console.WriteLine("No messages found in Deleted Items.");
            }
        }
        catch (ODataError odataError)
        {
            Console.WriteLine($"Error Code: {odataError.Error?.Code}");
            Console.WriteLine($"Error Message: {odataError.Error?.Message}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Exception: {ex.Message}");
        }
    }

    private static async Task<List<string>> GetDeletedItemsMessages(GraphServiceClient client)
    {
        var messageIds = new List<string>();
        var messages = await client.Me.MailFolders["deleteditems"].Messages.GetAsync();

        while (messages != null && messages.Value?.Count > 0)
        {
            foreach (var message in messages.Value)
            {
                messageIds.Add(message.Id);
            }

            if (messages.OdataNextLink != null)
            {
                messages = await client.Me.MailFolders["deleteditems"].Messages
                    .WithUrl(messages.OdataNextLink)
                    .GetAsync();
            }
            else
            {
                break;
            }
        }

        Console.WriteLine($"Found {messageIds.Count} messages in Deleted Items.");
        return messageIds;
    }

    private static async Task DeleteMessages(GraphServiceClient client, List<string> messageIds)
    {
        foreach (var messageId in messageIds)
        {
            await client.Me.Messages[messageId].DeleteAsync();
            Console.WriteLine($"Deleted message {messageId}");
        }
    }
}

Response:

To confirm that, I checked the same in user's Outlook "Deleted Items" folder where it is empty like below:

What I have tried: Using the /messages endpoint to delete email messages one by one or in batches, which works but only handles mail items. Investigating if there's a separate endpoint for non-mail items like /events or /contacts for this folder, but there seems to be no direct way to access them under "Deleted Items."

For Contacts there is a way of getting, deleting (or restoring) contacts from any folder eg

HTTPCopied
https://graph.microsoft.com/v1.0/me/contactfolders/deletedItems/contacts

Note the folder endpoint doesn't work /contactfolders/deletedItems because this folder isn't a contacts folder.

You can also get Messages from a contacts folder (it's rare for there to be messages in contacts but older clients did allow you to do this) eg

HTTPCopied
https://graph.microsoft.com/v1.0/me/mailfolders/contacts/messages 

For Calendar Items (Events) this doesn't work so there is no way of currently enumerating or restoring/deleting a calendar item. The same goes for Tasks but the Planner API is how you CRUD tasks in the Graph.

Older API's like MAPI and EWS will allow you access to all the items in the DeletedItems folder. MFCMapi is a pretty useful tool for understanding this https://github.com/microsoft/mfcmapi/releases this allows you to see that raw level access (that Outlook client and the Graph don't anymore). Eg with this you can see and delete the deleted Meetings and Appointment that might be stored in that folder.