<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Users\Item\SendMail\SendMailPostRequestBody;
use Microsoft\Graph\Generated\Models\Message;
use Microsoft\Graph\Generated\Models\ItemBody;
use Microsoft\Graph\Generated\Models\BodyType;
use Microsoft\Graph\Generated\Models\Recipient;
use Microsoft\Graph\Generated\Models\EmailAddress;
use Microsoft\Graph\Generated\Models\Attachment;
use Microsoft\Graph\Generated\Models\FileAttachment;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new SendMailPostRequestBody();
$message = new Message();
$message->setSubject('Meet for lunch?');
$messageBody = new ItemBody();
$messageBody->setContentType(new BodyType('text'));
$messageBody->setContent('The new cafeteria is open.');
$message->setBody($messageBody);
$toRecipientsRecipient1 = new Recipient();
$toRecipientsRecipient1EmailAddress = new EmailAddress();
$toRecipientsRecipient1EmailAddress->setAddress('meganb@contoso.com');
$toRecipientsRecipient1->setEmailAddress($toRecipientsRecipient1EmailAddress);
$toRecipientsArray []= $toRecipientsRecipient1;
$message->setToRecipients($toRecipientsArray);
$attachmentsAttachment1 = new FileAttachment();
$attachmentsAttachment1->setOdataType('#microsoft.graph.fileAttachment');
$attachmentsAttachment1->setName('attachment.txt');
$attachmentsAttachment1->setContentType('text/plain');
$attachmentsAttachment1->setContentBytes(\GuzzleHttp\Psr7\Utils::streamFor(base64_decode('SGVsbG8gV29ybGQh')));
$attachmentsArray []= $attachmentsAttachment1;
$message->setAttachments($attachmentsArray);
$requestBody->setMessage($message);
$graphServiceClient->me()->sendMail()->post($requestBody)->wait();