无法通过 Microsoft Graph API（C# 控制台）发送电子邮件

Question

我按照这 2 个链接创建了一个控制台应用程序，用于使用 Graph API 发送电子邮件：

https://docs.microsoft.com/en-us/graph/api/user-sendmail?view=graph-rest-1.0&tabs=csharp

Microsoft Graph API unable to Send Email C# Console

我已在 Azure AD 应用中添加并授予所需权限：

我确保提供了客户端 ID、租户 ID、客户端密码。

但是，我在运行控制台时看到此错误：

我错过了什么？

这是我从Microsoft Graph API unable to Send Email C# Console尝试的代码

static void Main(string[] args)
    {
        // Azure AD APP
        string clientId = "<client Key Here>";
        string tenantID = "<tenant key here>";
        string clientSecret = "<client secret here>";

        Task<GraphServiceClient> callTask = Task.Run(() => SendEmail(clientId, tenantID, clientSecret));
        // Wait for it to finish
        callTask.Wait();
        // Get the result
        var astr = callTask;
    }

    public static async Task<GraphServiceClient> SendEmail(string clientId, string tenantID, string clientSecret)
    {

        var confidentialClientApplication = ConfidentialClientApplicationBuilder
            .Create(clientId)
            .WithTenantId(tenantID)
            .WithClientSecret(clientSecret)
            .Build();

        var authProvider = new ClientCredentialProvider(confidentialClientApplication);       

        var graphClient = new GraphServiceClient(authProvider);

        var message = new Message
        {
            Subject = "Meet for lunch?",
            Body = new ItemBody
            {
                ContentType = BodyType.Text,
                Content = "The new cafeteria is open."
            },
            ToRecipients = new List<Recipient>()
            {
                new Recipient
                {
                    EmailAddress = new EmailAddress
                    {
                        Address = "myToEmail@gmail.com"
                    }
                }
            },
            CcRecipients = new List<Recipient>()
            {
                new Recipient
                {
                    EmailAddress = new EmailAddress
                    {
                        Address = "myCCEmail@gmail.com"
                    }
                }
            }
        };

        var saveToSentItems = true;

          await graphClient.Me
            .SendMail(message, saveToSentItems)
            .Request()
            .PostAsync();

        return graphClient;

    }

Answer 1

根据您生成confidentialClientApplication 的代码，您正在使用Client credentials provider。

但是您发送电子邮件的方式是：

await graphClient.Me
.SendMail(message, saveToSentItems)
.Request()
.PostAsync()

其实是调用https://graph.microsoft.com/v1.0/me/sendMail。

但客户端凭据流不支持/me 端点。在这种情况下，您应该调用 https://graph.microsoft.com/v1.0/users/{id | userPrincipalName}/sendMail 端点。

所以代码应该是：

await graphClient.Users["{id or userPrincipalName}"]
    .SendMail(message, saveToSentItems)
    .Request()
    .PostAsync();

或者如果你想使用/me/sendMail，选择Authorization code provider，你应该在这里实现交互式登录。

您可以了解authorization code flow和client credentials flow之间的场景和区别。