如何从启用了多因子身份验证的office 365帐户使用VB.NET或C#代码发送电子邮件？

using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        string tenantId = "your-tenant-id";
        string clientId = "your-client-id";
        string clientSecret = "your-client-secret";
        string resource = "https://graph.microsoft.com/";
        string authority = $"https://login.microsoftonline.com/{tenantId}";
        string redirectUri = "https://login.microsoftonline.com/common/oauth2/nativeclient";

        // Step 1: Get authorization code
        string authorizationCode = await GetAuthorizationCode(authority, clientId, redirectUri);

        // Step 2: Get access token
        string accessToken = await GetAccessToken(authority, clientId, clientSecret, authorizationCode, redirectUri);

        // Step 3: Send email using Microsoft Graph API
        await SendEmail(accessToken);
    }

    static async Task<string> GetAuthorizationCode(string authority, string clientId, string redirectUri)
    {
        // Implement OAuth 2.0 authorization code flow to get the authorization code
        // This is a simplified example, in practice you would need to handle the browser redirection and user consent
        return "your-authorization-code";
    }

    static async Task<string> GetAccessToken(string authority, string clientId, string clientSecret, string authorizationCode, string redirectUri)
    {
        using (var client = new HttpClient())
        {
            var content = new FormUrlEncodedContent(new[]
            {
                new KeyValuePair<string, string>("grant_type", "authorization_code"),
                new KeyValuePair<string, string>("client_id", clientId),
                new KeyValuePair<string, string>("client_secret", clientSecret),
                new KeyValuePair<string, string>("code", authorizationCode),
                new KeyValuePair<string, string>("redirect_uri", redirectUri),
                new KeyValuePair<string, string>("resource", resource)
            });

            var response = await client.PostAsync(authority + "/oauth2/token", content);
            var result = await response.Content.ReadAsStringAsync();
            var tokenData = System.Text.Json.JsonDocument.Parse(result).RootElement.GetProperty("access_token").GetString();
            return tokenData;
        }
    }

    static async Task SendEmail(string accessToken)
    {
        using (var client = new HttpClient())
        {
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
            var content = new StringContent(@"
            {
                ""message"": {
                    ""subject"": ""Hello"",
                    ""body"": {
                        ""contentType"": ""Text"",
                        ""content"": ""Hello, World!""
                    },
                    ""toRecipients"": [
                        {
                            ""emailAddress"": {
                                ""name"": ""John Doe"",
                                ""address"": ""john.doe@contoso.com""
                            }
                        }
                    ]
                }
            }", System.Text.Encoding.UTF8, "application/json");

            var response = await client.PostAsync("https://graph.microsoft.com/v1.0/me/sendMail", content);
            if (response.IsSuccessStatusCode)
            {
                Console.WriteLine("Email sent successfully.");
            }
            else
            {
                Console.WriteLine($"Failed to send email. Status code: {response.StatusCode}");
            }
        }
    }
}