MSGraph API: sending email using Python app

Question

MSGraph API: sending email using Python app

Francesco Castellani 60

I am new to Microsoft Graph. I need to send an email automatically internally, and I already have a valid client_id which has the following API permissions:

Mail.Send (Delegated)
Mail.Send (Application)
User.Read (Delegated)
Application.Read.All (Delegated)

However, when I run the code below, trying to send an email to myself (valid Company address), I don't receive any email and if I look at the result object I see that it is the following: <coroutine object NotificationManager.send_email at 0x0000012BC81452A0>

Instead, I was expecting the typical JSON response from an API, with 4xx if errored.

This is my code: what am I doing wrong?

import msal from Utils.utils import Utils # Custom utility class
from azure.identity import DeviceCodeCredential
from msgraph.graph_service_client import GraphServiceClient
from typing import Optional 
from msgraph.generated.models.message import Message
from msgraph.generated.users.item.send_mail.send_mail_post_request_body import SendMailPostRequestBody
from msgraph.generated.models.importance import Importance
from msgraph.generated.models.item_body import ItemBody
from msgraph.generated.models.body_type import BodyType
from msgraph.generated.models.recipient import Recipient
from msgraph.generated.models.email_address import EmailAddress


class NotificationManager:

    def __init__(self) -> None:
        '''Class constructor.'''

        self.ms_graph_base_url = "https://graph.microsoft.com/v1.0"
        self.client_id = Utils.load_config('client_id')
        self.client_secret = Utils.load_config('client_secret')
        self.tenant_id = Utils.load_config("tenant_id")
        self.authority = f"https://login.microsoftonline.com/{self.tenant_id}"
        self.scopes = ["https://graph.microsoft.com/.default"]
        self.sender = "<sender_email>"
        

    def get_client(self) -> GraphServiceClient:
        '''Get a requests session with the access token.'''

        try:
            credential = DeviceCodeCredential(self.client_id)
            graph_client = GraphServiceClient(credential, self.scopes)
            return graph_client
        
        except Exception as e:
            logging.error(f"An error occurred: {e}")
            raise Exception("Failed to get Graph client.")
        

    async def send_email(self, graph_client: GraphServiceClient, recipient: str, subject: str, content: str) -> None:
        '''Send an email using the Graph API.'''

        try:
            request_body = SendMailPostRequestBody(
                message = Message(
                    subject = subject,
                    importance = Importance.Low,
                    body = ItemBody(
                        content_type = BodyType.Html,
                        content = self.form_html_message(content),
                    ),
                    sender = EmailAddress(
                        address = self.sender,
                    ),
                    to_recipients = [
                        Recipient(
                            email_address = EmailAddress(
                                address = recipient,
                            ),
                        ),
                    ],
                ),
                save_to_sent_items = True
            )

            #result = await graph_client.me.messages.post(request_body)
            result = await graph_client.me.send_mail.post(request_body)
            return result
        
        except Exception as e:
            logging.error(f"An error occurred: {e}")
            raise Exception(f"Failed to send email from {self.sender} to {recipient}.")
        

    def form_html_message(self, content: str) -> str:
        '''Format the message to be sent in HTML.'''

        try:
            html_content = f"""
            <html>
                <head>
                    <style>
                        body {{
                            font-family: Arial, sans-serif;
                            font-size: 14px;
                            color: #333;
                        }}
                        h1 {{
                            color: #0078d4;
                        }}
                    </style>
                </head>
                <body>
                    <h1>Header</h1>
                    <p>{content}</p>
                </body>
            </html>
            """
            return html_content
        
        except Exception as e:
            logging.error(f"An error occurred: {e}")
            raise Exception("Failed to format HTML message.")

SrideviM 2,785 Reputation points Microsoft External Staff

2025-04-19T03:53:08.6333333+00:00

Hello Francesco Castellani,

I understand you're using device code flow, which means the app can only send emails from the signed-in user. Can you check if the sender email matches that user? Also, please confirm if admin consent was granted for the permissions in Azure. If you need to send mail from a different account, switching to client credentials flow would be a better fit. Let me know how you'd like to proceed.

1 answer

Your answer

SrideviM 2,785 Reputation points Microsoft External Staff

2025-04-19T03:53:08.6333333+00:00

Hello Francesco Castellani,

I understand you're using device code flow, which means the app can only send emails from the signed-in user. Can you check if the sender email matches that user? Also, please confirm if admin consent was granted for the permissions in Azure. If you need to send mail from a different account, switching to client credentials flow would be a better fit. Let me know how you'd like to proceed.

Answer 1

Hello Francesco Castellani,

I understand you're using device code flow with Microsoft Graph. In this method, the app can only send emails from the user who logs in. So, the sender must be the same as the signed-in user.

Also, the error line showing <coroutine object ...> is happening because the send function is async, and it needs to be called with await.

I registered one application and added same API permissions with admin consent:

enter image description here

When I tried your code without using await, I too got the same error in my environment:

enter image description here

After fixing that, the email was sent successfully. Here’s the working code using device code flow:

import asyncio
import logging
from azure.identity import DeviceCodeCredential
from msgraph.graph_service_client import GraphServiceClient
from msgraph.generated.models.message import Message
from msgraph.generated.models.item_body import ItemBody
from msgraph.generated.models.body_type import BodyType
from msgraph.generated.models.recipient import Recipient
from msgraph.generated.models.email_address import EmailAddress
from msgraph.generated.users.item.send_mail.send_mail_post_request_body import SendMailPostRequestBody

class NotificationManager:
    def __init__(self) -> None:
        self.client_id = "appID"
        self.tenant_id = "tenantId"
        self.scopes = ["https://graph.microsoft.com/.default"]
        self.sender = "******@xxxxxxxx.onmicrosoft.com"

    def get_client(self) -> GraphServiceClient:
        try:
            credential = DeviceCodeCredential(client_id=self.client_id, tenant_id=self.tenant_id)
            return GraphServiceClient(credential, self.scopes)
        except Exception as e:
            logging.error(f"Failed to get Graph client: {e}")
            raise

    async def send_email(self, graph_client: GraphServiceClient, recipient: str, subject: str, content: str) -> None:
        try:
            message = Message(
                subject=subject,
                importance="low",
                body=ItemBody(
                    content_type=BodyType.Html,
                    content=self.form_html_message(content),
                ),
                to_recipients=[
                    Recipient(
                        email_address=EmailAddress(address=recipient),
                    )
                ]
            )

            request_body = SendMailPostRequestBody(
                message=message,
                save_to_sent_items=True
            )

            response = await graph_client.me.send_mail.post(request_body)

            if response is None:
                print("Mail sent successfully.")
            else:
                print("Unexpected response:", response)
        except Exception as e:
            logging.error(f"Failed to send email from {self.sender} to {recipient}: {e}")
            raise

    def form_html_message(self, content: str) -> str:
        return f"""
        <html>
            <head>
                <style>
                    body {{
                        font-family: Arial, sans-serif;
                        font-size: 14px;
                        color: #333;
                    }}
                    h1 {{
                        color: #0078d4;
                    }}
                </style>
            </head>
            <body>
                <h1>Test mail</h1>
                <p>{content}</p>
            </body>
        </html>
        """
async def main():
    manager = NotificationManager()
    client = manager.get_client()
    await manager.send_email(
        graph_client=client,
        recipient="******@xxxxxxxxx.onmicrosoft.com",
        subject="Test Subject",
        content="This is a test email sent using Microsoft Graph SDK."
    )

if __name__ == "__main__":
    asyncio.run(main())

When you run the code, it shows a message with a link and device code—clicking the link opens a browser where you enter the code to sign in:

enter image description here

Make sure to sign in with user account from which you want to send mail:

enter image description here

Output:

enter image description here

Mail sent with Device Code flow:

enter image description here

If you want to send mail from any account without someone logging in, you can use client credentials flow. This method works with Application type permissions and lets the app send mail from any user with a mailbox.

Here’s the working code for that:

import asyncio
import logging
from azure.identity import ClientSecretCredential
from msgraph.graph_service_client import GraphServiceClient
from msgraph.generated.models.message import Message
from msgraph.generated.models.item_body import ItemBody
from msgraph.generated.models.body_type import BodyType
from msgraph.generated.models.recipient import Recipient
from msgraph.generated.models.email_address import EmailAddress
from msgraph.generated.users.item.send_mail.send_mail_post_request_body import SendMailPostRequestBody

class NotificationManager:
    def __init__(self) -> None:
        self.client_id = "appId"
        self.tenant_id = "tenantId"
        self.client_secret = "secret"
        self.sender = "******@xxxxxxxxxx.onmicrosoft.com"
        self.scopes = ["https://graph.microsoft.com/.default"]

    def get_client(self) -> GraphServiceClient:
        try:
            credential = ClientSecretCredential(
                tenant_id=self.tenant_id,
                client_id=self.client_id,
                client_secret=self.client_secret
            )
            return GraphServiceClient(credential, self.scopes)
        except Exception as e:
            logging.error(f"Failed to get Graph client: {e}")
            raise

    async def send_email(self, graph_client: GraphServiceClient, recipient: str, subject: str, content: str) -> None:
        try:
            message = Message(
                subject=subject,
                importance="low",
                body=ItemBody(
                    content_type=BodyType.Html,
                    content=self.form_html_message(content),
                ),
                to_recipients=[
                    Recipient(email_address=EmailAddress(address=recipient))
                ]
            )

            request_body = SendMailPostRequestBody(
                message=message,
                save_to_sent_items=True
            )

            response = await graph_client.users.by_user_id(self.sender).send_mail.post(request_body)

            if response is None:
                print("Mail sent successfully.")
            else:
                print("Unexpected response:", response)
        except Exception as e:
            logging.error(f"Failed to send email from {self.sender} to {recipient}: {e}")
            raise

    def form_html_message(self, content: str) -> str:
        return f"""
        <html>
            <head>
                <style>
                    body {{
                        font-family: Arial, sans-serif;
                        font-size: 14px;
                        color: #333;
                    }}
                    h1 {{
                        color: #0078d4;
                    }}
                </style>
            </head>
            <body>
                <h1>Test mail</h1>
                <p>{content}</p>
            </body>
        </html>
        """
async def main():
    manager = NotificationManager()
    client = manager.get_client()
    await manager.send_email(
        graph_client=client,
        recipient="******@xxxxxxxx.onmicrosoft.com",
        subject="Test Subject (App Auth)",
        content="This is a test email sent using Microsoft Graph SDK via client credentials."
    )

if __name__ == "__main__":
    asyncio.run(main())

Output:

enter image description here

Mail sent with client credentials flow:

enter image description here

Hope this helps clarify things.

If this answer was helpful, please click "Accept the answer" and mark Yes, as this can help other community members.

User's image

If you have any other questions or are still experiencing issues, feel free to ask in the "comments" section, and I'd be happy to help.

SrideviM 2,785 Reputation points Microsoft External Staff

2025-04-20T01:35:24.9966667+00:00

Hello Francesco Castellani,

Following up to see if the above answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
SrideviM 2,785 Reputation points Microsoft External Staff

2025-04-21T00:41:29.4233333+00:00

Hello Francesco Castellani,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. If your question has been solved, then you can click Accept Answer and Yes for was this answer helpful, which may help members with similar questions.
Francesco Castellani 60 Reputation points

2025-05-02T10:20:49.0866667+00:00

Hi, the correct use case for me is using the client credentials flow where emails are sent on behalf of a Microsoft 365 Group. However, if I use the email address of a Microsoft 365 Group as sender, which has been created in the same tenant and has a valid email, I get: API: Error Code: 404: message="The requested user '******@domain.com' is invalid."
SrideviM 2,785 Reputation points Microsoft External Staff

2025-05-02T10:28:31.07+00:00

Hello Francesco Castellani,

Microsoft Graph doesn't support sending emails from Microsoft 365 Groups using app-only flow. You’ll need to use a licensed user mailbox like ******@domain.com as the sender. Group mailboxes aren't treated as valid user identities for the sendMail API.
Francesco Castellani 60 Reputation points

2025-05-02T10:32:39.57+00:00

And how do I know that my Microsoft 365 Group is a licensed user mailbox? And what could be a workaround to this?
SrideviM 2,785 Reputation points Microsoft External Staff

2025-05-02T10:37:56.3+00:00

Hello Francesco Castellani,

Microsoft 365 Groups do not have user identities or licenses like regular user mailboxes, so they cannot act as senders in app-only (client credentials) flow. They are shared resources, not individual users, and Microsoft Graph treats them differently.

A practical workaround is to create a service account (a regular user with a mailbox and an Exchange Online license), assign it as a member or owner of the group, and use its email address as the sender when calling the sendMail API. This way, your app can send emails reliably using app-only permissions.
SrideviM 2,785 Reputation points Microsoft External Staff

2025-05-02T11:36:16.21+00:00

Hello Francesco Castellani,

Please do let me know if you have any other queries. Refer this Stack Overflow link if it helps.

If this answer was helpful, please click "Accept answer" and mark Yes, as this can be beneficial to other community members.

Share via

MSGraph API: sending email using Python app

1 answer

Your answer