ms graph php sdk set from name when sending email - php

Question

Working off of the 'Send and email' example:
https://github.com/microsoftgraph/msgraph-sdk-php/wiki/Example-calls#send-an-email
I'm trying to set the 'from name' of the email in the header of the sent email to show 'TEST' instead of the name associated with my OWA account.
$graph = new Graph();
$graph->setAccessToken(access_token);
$mailBody = array( "Message" => array(
"subject" => $subject . ' ' . $from_name,
"body" => array(
"contentType" => "html",
"content" => $body
),
"sender" => array(
"emailAddress" => array(
"name" => "TEST",
"address" => $from_user->email
)
),
"from" => array(
"emailAddress" => array(
"name" => 'TEST',
"address" => $from_user->email
)
),
"toRecipients" => array(
array(
"emailAddress" => array(
"name" => $to_user->name,
"address" => $to_user->email
)
)
)
)
);
$response = $graph->createRequest("POST", "/me/sendMail")
->attachBody($mailBody)
->execute();
But the message header always has the name from my OWA (outlook) account instead.

Answer 1

AFAIK it is not supported to override name property of emailAddress resource via senMail endpoint.
But Microsoft Graph supports the feature which allows a user to send mail that appears to be sent from another user, distribution list, group, resource, or shared mailbox (official documentation)
Two mailbox permissions affect how a message is sent:
Send on Behalf
Send As
Below is demonstrated on how to sent mail from distribution group called Finance Department
POST https://graph.microsoft.com/v1.0/me/sendMail
{
"message": {
"subject": "Finance results",
"body": {
"contentType": "text",
"content": "Some finance results goes here..."
},
"toRecipients": [
{
"emailAddress": {
"address": "mary#contoso.onmicrosoft.com"
}
}
],
"from": {
"emailAddress": {
"address": "financedeplist#contoso.onmicrosoft.com"
}
}
}
}
Current user: Jon Doe (jdoe#contoso.onmicrosoft.com)
Option 1. Send on Behalf
Option 2. Send As