调用Microsoft Graph API的user:sendMail接口时遇500内部服务器错误

错误信息 #

向https://graph.microsoft.com/v1.0/users/myemail@contoso.com/sendMail发送POST请求时，收到500内部服务器错误，响应如下：

JSON Response  {'error': {'code': 'ErrorInternalServerError', 'message': 'An internal server error occurred. The operation failed.'}}
SystemExit: 500 Server Error: Internal Server Error for url: https://graph.microsoft.com/v1.0/users/myemail@contoso.com/sendMail

相关情况 #

• 使用相同认证方式访问https://graph.microsoft.com/v1.0/users/端点功能正常；
• 相同的JSON数据在Graph Explorer中可正常发送邮件；
• 在Entra ID的「监控与健康>审核日志」中无法找到相关日志。

附代码 #

import json
import msal
import requests
'''
Sjabloonscript 26-9-23 Graph API
Zie https://developer.microsoft.com/en-us/graph/graph-explorer voor typen eindpunten
'''
#send from?
versturende_email = "myemail@contoso.com"
#demomode?
demo = True
#config
config = {
        "client_id": "------",
        "scope": ["https://graph.microsoft.com/.default"],
        "secret": "SECRETHERE",
        "tenant-id": "tenid",
        "authority": 'https://login.microsoftonline.com/-----',
        "eindpunt": 'https://graph.microsoft.com/v1.0/users/'+versturende_email+'/sendMail'
    }

def O365_toegangstoken():
    '''
    Haal toegangstoken op met je app registratie , let op de duur van de token
    '''
    #Get token
    scopes = ["https://graph.microsoft.com/.default"]
    app = msal.ConfidentialClientApplication(
        config["client_id"],
        authority=config["authority"],
        client_credential=config["secret"],
    )
    # Since MSAL 1.23, acquire_token_for_client(...) will automatically look up
    # a token from cache, and fall back to acquire a fresh token when needed.
    resultaat = app.acquire_token_for_client(scopes=config["scope"])
    #check if token was returned
    if "access_token" in resultaat:
              toegangstoken = 'Bearer ' + resultaat['access_token']
              return toegangstoken
    else:
        print(result.get("error"))
        print(result.get("error_description"))
        print(result.get("correlation_id"))  # Nodig voor als je een bug wil rapporteren
        raise Exception("Tokenerrrrror")


def main():
    #get token
    token = O365_toegangstoken()
    #headers
    hoofd = {
      'Authorization': token
    }
    #de toegangstoken is goed gegenereerd
    #generate mail json
    mailbericht = {}
    html = """
    <html>
      <head></head>
      <body>
        <p>Beste {0},<br><br>
           blablatestmessage
           {2}{3}
           <b>Let op!</b> blablabla
           <br><br>
           <i>Dit betreft een automatisch gegenereerd bericht</i>
           <br><br>
           Met vriendelijke groet,
           <br><br>
           Automatisering.
        </p>
        {4}
      </body>
    </html>
    """.replace("\n", "")
    mailbericht["message"] = {
        'subject' : 'Hallo',
        'body' : {
            'contentType' : 'HTML',
            'content' : html
        }
    }
    mailbericht["message"]['toRecipients'] = []
    mailbericht["message"]['toRecipients'].append({'emailAddress': {
        "address": naar
    }})
    #print json and header?
    if demo:
         print("{0}\n{0}Header{0}\n{2}\n{0}\n{1}\n{0}".format("-"*50,json.dumps(mailbericht,indent=5),hoofd))
    try:
        #post to graph
        r = requests.post(url= config["eindpunt"], headers=hoofd, json = json.dumps(mailbericht))
        r.raise_for_status()
        #error handling
    except requests.exceptions.HTTPError as err:
        print("Status Code", r.status_code)
        print("JSON Response ", r.json())
        raise SystemExit(err)

    #non-error handling
    print("Status Code", r.status_code)
    print("JSON Response ", r.json())
        
main()

排查建议 #

1. 修复请求体传递方式 #

代码中使用json = json.dumps(mailbericht)传递请求体是错误的：requests库的post方法的json参数接受Python字典，会自动将其序列化为JSON字符串并设置Content-Type: application/json头。手动转成字符串会导致Graph API无法正确解析请求体，引发内部错误。

修改为：

r = requests.post(url=config["eindpunt"], headers=hoofd, json=mailbericht)

2. 检查未定义变量naar #

代码中"address": naar里的naar变量未定义，这会导致请求体缺失收件人信息，引发错误。请确保naar变量已被赋值为有效的收件人邮箱地址。

3. 启用请求调试日志 #

添加以下代码到脚本中，查看实际发送的请求头和请求体，对比Graph Explorer的请求内容，定位差异：

import logging
import http.client

http.client.HTTPConnection.debuglevel = 1
logging.basicConfig()
logging.getLogger().setLevel(logging.DEBUG)
requests_log = logging.getLogger("requests.packages.urllib3")
requests_log.setLevel(logging.DEBUG)
requests_log.propagate = True

4. 确认应用权限配置 #

确保应用注册已添加Mail.Send应用权限（或委托权限，根据认证方式），且已获得管理员同意。虽然users端点能访问，但sendMail需要特定权限。

5. 获取Correlation ID #

检查响应头中的Correlation-ID字段（可通过调试日志查看），该ID可用于向微软支持查询详细错误原因，或在Graph API的日志系统中定位问题。

内容的提问来源于stack exchange，提问作者Zr.Ms. Bruinvis