Gmail API Request Excel VBA PHP - php

Question

I'm using Excel VBA to get a user's oAuth2 token for the mail.google.com scope for a native application. It works fine so I have the the user's Access Token (it refreshes if it expires) and I have the user's email address. I was using Zend SMTP to send the emails but found out there are limits to bulk sending emails this way (currently my account is locked out due to going over quota while trying to figure this out over the weekend). My client may send 2,000 emails at once and locking themselves out of their Gmail account for 24 hours is unacceptable. I think using the Gmail REST API will work, as it has higher quotas, but not finding any detailed PHP examples of how to create and send an HTML email via an HTTP request.
I know I have to create the MIME email and think I can figure that out (using this thread stackoverflow.com/questions/24940984/send-email-using-gmail-api-and-google-api-php-client) or from the Zend emails I was successfully creating. My question is what PHP code do I use to create and send the email?
The Google Dev examples all reference /userId/ (from developers.google.com/gmail/api/v1/reference/) but not sure where to get that if I just have the users token and their email address.
I assume it's something like this:
<?php
require 'GoogleAPI/src/Google/autoload.php';
extract($_POST); // use to get my client token, client's email address, the email to, cc, bcc, subject, body, etc.
//<Build the email $mime message here>
$m = new Google_Service_Gmail_Message();
$data = base64_encode($mime);
$data = str_replace(array('+','/','='),array('-','_',''),$data); // url safe
$m->setRaw($data);
$service->users_messages->send('me', $m);
?>
I don't know where to put the user's token. I know 'me' is the person that is authenticated.
I'm open to using an HTTP request as well, something like https://mywebsite.com/sendgmail.php?token=[UsersToken]&UserEmail=joe#test.com&ToEmail=toperson#xyz.com&Subject=HI&Body=Thanks for your help instead of the post method.
Just not sure how to implement that either.
I'm self taught PHP and VBA and new to the google api world so please forgive me if this is easy. I'm also looking into boxspring but trying to use the native APIs and PHP first.
EDIT:
So I've tried this using the examples but getting an error that my token is not in proper JSON format. I just want to send the token as a string. If I can't is there a way to make the string into JSON so oauth2 will accept it?:
<?php
require 'GoogleAPI/src/Google/autoload.php';
/**
* Returns an authorized API client.
* #return Google_Client the authorized client object
*/
$client = new Google_Client();
$client->setAccessToken('ya29.hwFcwk2M73vaPwNObeuwizHGjXT2y6UsAFEcDIvRAoWTM28gu2pJeK4GiMySkfAllTOQvXVMYfffff');
// Get the API client and construct the service object.
//$client = getClient();
$service = new Google_Service_Gmail($client);
// Print the labels in the user's account.
$user = 'me';
$results = $service->users_labels->listUsersLabels($user);
if (count($results->getLabels()) == 0) {
print "No labels found.\n";
} else {
print "Labels:\n";
foreach ($results->getLabels() as $label) {
printf("- %s\n", $label->getName());
}
}
?>
Error:
Fatal error: Uncaught exception 'Google_Auth_Exception' with message
'Could not json decode the token' in
/home/[my domain]/public/GoogleAPI/src/Google/Auth/OAuth2.php:179
Stack trace: #0
/home/[my domain]/public/GoogleAPI/src/Google/Client.php(215):
Google_Auth_OAuth2->setAccessToken('ya29.hwFcwk2M73...') #1
/home/[my domain]/public/labels.php(17):
Google_Client->setAccessToken('ya29.hwFcwk2M73...') #2 {main} thrown
in
/home/[my domain]/public/GoogleAPI/src/Google/Auth/OAuth2.php
on line 179
I'm sure I'm making this more difficult than it should be. I'm using the PHP example of showing a users labels, even though my final goal is to send emails.