Gmail API with PHP mailer can't send multiple attachments - php

Question

I am using PHPmailer with Gmail API to send out mail. This process has worked very well for me for sending just standard emails, however, I want to also have the ability to send out an email with attachments using the Gmail API. When I tried using $mail->addAttachment($urlString, $name); Gmail would come back with the error Request Entity Too Large Error 413 (The size of the attachments never goes above 20MB so it should be well within the 35MB limits of Gmail API).
After some searching, I found out it was because I wasn't using "/Upload URI" for sending large Gmail Attachments (Anything above 5mb and below 35mb). Problem is, I am not very knowledgeable on how to work the Gmail API and only got what I have now from basically copying code from somewhere else and slightly modifying it for my uses and as such, I have no idea how to change the URI like that.
Here is what I have so far, that works with standard emails:
function($agent, $assistantName='', $assistantEmail='', $subject, $body, $attachments=''){
$key = realpath(dirname(__FILE__).'/Services/Google/Gmail.json');
$useremail = 'myuseremail#example.com';
$toAddress = $agent->email;
$agentFirst = $agent->first_name;
$client = new Google_Client();
putenv('GOOGLE_APPLICATION_CREDENTIALS='.$key);
$client->useApplicationDefaultCredentials();
$user_to_impersonate = $useremail;
$client->setSubject($user_to_impersonate);
$client->addScope('https://www.googleapis.com/auth/gmail.compose');
if ($client->isAccessTokenExpired()) {
$client->refreshTokenWithAssertion();
}
//prepare the mail with PHPMailer
$mail = new PHPMailer();
$mail->CharSet = "UTF-8";
$mail->Encoding = "base64";
$subject = $subject;
$msg = $body;
$from = $useremail;
$fname = "My Name";
$mail->From = $from;
$mail->FromName = $fname;
$mail->AddAddress($toAddress, $agentFirst);
$mail->AddCC($assistantEmail, $assistantName);
$mail->AddReplyTo($from,$fname);
if ($attachments != '') {
foreach ($attachments as $name => $urlString) {
$mail->addAttachment($urlString, $name);
}
}
$mail->Subject = $subject;
$mail->Body = $msg;
$mail->IsHTML(true);
$mail->preSend();
$mime = $mail->getSentMIMEMessage();
$m = new Google_Service_Gmail_Message();
$data = base64_encode($mime);
$data = str_replace(array('+','/','='),array('-','_',''),$data); // url safe
$m->setRaw($data);
$service = new Google_Service_Gmail($client);
$email = $service->users_messages->send($useremail, $m);
return json_encode($email);
}
I don't really know where to go from here, so any help would be appreciated.

Answer 1

use EZCMail and build the email structure yourself... it is very pickey! I can post some details after.
you may also have to send the email in chunks.
If the email is over 4MB then you are going to have to send in chunks using Google_Http_MediaFileUpload
Your code using this should be something similar to this, there is examples for using Google_Http_MediaFileUpload elsewhere on the web which might be more complete:
$client->setDefer(true);
// Call the API with the media upload, defer so it doesn't immediately return.
$arrRequestParams = $arrRequestParams+['uploadType' => 'multipart'];
$result = $this->TransportPrepSwitch($strAction, $objGMessage, $arrRequestParams); // Make draft or message $service->users_messages->send('me', $objGMessage, $arrRequestParams);
$mailMessage = base64url_decode($strRaw);
// create mediafile upload
$chunkSizeBytes = 1*1024*1024; // send to google in 1MB chunks
$media = new Google_Http_MediaFileUpload($client,$result,'message/rfc822',$mailMessage,true,$chunkSizeBytes);
$media->setFileSize(strlen($mailMessage));
// Upload chunks. Status will contain the completed $result.
$status = false;
set_time_limit(300);
while(!$status)
$status = $media->nextChunk();
// Reset to the client to execute requests immediately in the future.
$client->setDefer(false);
$objResponce = $status;
Also the structure of the email parts MUST be as follows:
multipart/mixed => [
multipart/related => [
multipart/alternative => [
plain,
html
],
inline images,
],
attachments,
]
The only way I could achieve this was using EZCMail to build the email part by part.