Send Emails using Microsoft Graph and Shared Mailboxes

Send Email from an Application using Microsoft Graph and Microsoft 365 shared mailbox without an logged in user.

Log into Exchange Admin center and create a shared mailbox.

Create an Enterprise Application

Choose Microsoft Graph

Choose Application

Add Mail.Send Permission

Grant Admin Consent

Grant Admin Consent Confirmation

Grant is successful

Create a Secret

Copy the secret and keep in a notepad

Collect your Client ID – Application (Client) ID

There are two steps – Take Token – then use the token to send email.

Use Postman to get Token.

Download Postman 64 Bit and install on Windows or Mac

Copy the Access Token – Take it without double quotes

Now lets POST on graph url to send some test emails. Put this as Headers

{
    "message": {
        "subject": "Sending from Graph",
        "body": {
            "contentType": "Text",
            "content": "Sending from Graph using PostMan"
        },
        "toRecipients": [
            {
                "emailAddress": {
                    "address": "sathesh@azure365prox.com"
                }
            }
        ],
        "ccRecipients": [
            {
                "emailAddress": {
                    "address": "info@azure365pro.com"
                }
            }
        ]
    },
    "saveToSentItems": "false"
}

Email is generated

If the scope of permission is wide. In Enterprise scenario you can harden it using New-ApplicationAccessPolicy which i have explained in this article to reach attachments using Graph. Access Specific Office 365 Mailbox using Microsoft Graph – Azure365Pro.com