c# - 通过 Microsoft Graph 发送邮件返回内部服务器错误

Question

我有一个要求，我需要通过 Office 365 帐户发送电子邮件，经过大量谷歌搜索后，我找到了使用 Microsoft Graph 的 Office 365 Connect ASP.NET MVC 示例。

Graph 使用以下 API 发送电子邮件

https://graph.microsoft.com/v1.0/me/sendmail

下面是调用 API 的代码

using(var client = new HttpClient())
{
    using(var request = new HttpRequestMessage(HttpMethod.Post, SendMessageUrl))
    {
        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);

        string content = @"{
            ""message"": {
                ""subject"": ""Meet for lunch?"",
                ""body"": {
                ""contentType"": ""Text"",
                ""content"": ""The new cafeteria is open.""
                },
                ""toRecipients"": [
                {
                    ""emailAddress"": {
                    ""address"": ""myemailaddress""
                    }
                }
                ]
            },
            ""saveToSentItems"": ""false""
            }";
        request.Content = new StringContent(content, Encoding.UTF8, "application/json");
        using(HttpResponseMessage response = await client.SendAsync(request))
        {
            if (response.IsSuccessStatusCode)
            {
                sendMessageResponse.Status = SendMessageStatusEnum.Sent;
                sendMessageResponse.StatusMessage = null;
            }
            else
            {
                sendMessageResponse.Status = SendMessageStatusEnum.Fail;
                sendMessageResponse.StatusMessage = response.ReasonPhrase;
            }
        }
    }
}

但是每次我的请求因“内部服务器错误”原因而失败

如果这是 API 的问题或我的问题，我会感到困惑。