SMTP permissions

Question

Hi All,

I am using an Exchange 2016 Hybrid environment. One of my users wants to send emails to DLs using a Python script. I don't want the user to use Office365 SMTP relay due to basic authentication concerns, so I have recommended using an Azure Service Principal(Azure App Registration) instead.

I have created a client id(Azure App Registration) for the user. Will the following Microsoft Graph permissions be sufficient: SMTP.Send and User.Read? Also, are the offline_access and IMAP.AccessAsUser.All permissions required?

Please guide me if any other permissions are necessary..

Answer 1

Hi @Glenn Maxwell

If you are using a service principal instead of a logged-in user to send emails, delegated permissions will not apply. Delegated permissions are for delegated contexts, not app-only contexts.

When sending emails using the Microsoft Graph Mail API, you only need to grant the Mail.Send application permission to the calling app (service principal). Don't forget to grant admin consent for this permission.

Hope this helps.

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Answer 2

Hello Glenn Maxwell,

Thank you for reaching out to Microsoft Support!

To send an email using the Microsoft Graph API, you can follow these steps:

1. Create the Request:
   • Endpoint: POST https://graph.microsoft.com/v1.0/users/user-id/sendMail
   • Headers: Authorization: Bearer {token} Content-Type: application/json
   • Required Scopes - Please use Application permissions ("Mail.Send").
   • Body: Construct the email message in JSON format. Here’s an example:

          {
            "message": {
              "subject": "Meet for lunch?",
              "body": {
                "contentType": "Text",
                "content": "The new cafeteria is open."
              },
              "toRecipients": [
                {
                  "emailAddress": {
                    "address": "example@example.com"
                  }
                }
              ]
            },
            "saveToSentItems": "true"
          }
     

2. Check the Response: A successful request will return a 202 Accepted status code.

Please check documentation.

By following above steps, you can send mail using Microsoft Graph API.

Hope this helps.

If the answer is helpful, please click Accept Answer and kindly upvote it. If you have any further questions about this answer, please click Comment.