sending multiple emails issue phpMailer - php

Question

I'm trying to send multiple emails (more than 100) to existing as well as non-existing recipients, since that is what my requirement is.
I'm using phpMailer that uses Gmail SMTP server.
Recipients are stored in array, and looped through this array to add as recipients.
public static function mailTo($recipients)
{
$f3 = \Base::instance();
$user = AclHelper::getCurrentUser();
$template= new \Template;
$mailBody= $template->render('leave/emailTemp.html');
// When true, PHPMailer returns exceptions
$mail = new PHPMailer(true);
try {
$mail->isSMTP(); // Set mailer to use SMTP
$mail->isHTML(true);
$mail->addAddress($user['email']);
$mail->addAddress("abhshrestha#growbydata.com");
$mail->addAddress("rmali#growbydata.com");
foreach($recipients as $recipient){
$mail->addAddress($recipient);
}
$mail->SMTPAuth = true; // authentication enabled
$mail->SMTPSecure = 'ssl'; // secure transfer enabled REQUIRED for Gmail
$mail->Host = "smtp.gmail.com";
$mail->Port = 465; // or 587
$mail->Username = "growbydata.np#gmail.com";
$mail->Password = "abcd";
$mail->setFrom($user['email']);
$userFullName = trim(ucfirst($user['firstname'])) . " " . trim(ucfirst($user['lastname']));
$mail->FromName = $userFullName;
$mail->Body = $f3->get('message');
$mail->Body .="<br>". $mailBody;
$mail->Subject = 'Updates on leave date applied';
$mailStatus = (boolean)$mail->send();
if ($mailStatus === true) {
return $mail;
}
} catch (phpmailerException $e) {
$response = array(
'status'=>'error',
'message'=>'Got some error while sending emails',
'exceptions'=>$e->getMessage()
);
return $response;
} catch (Exception $e) {
$response = array(
'status'=>'error',
'message'=>'Got some error while sending emails',
'exceptions'=>$e->getMessage()
);
return $response;
}
}
Recipients are both existing addresses as well as non-existing eg. abc#gbd.gbdtest.
When I send emails to all these recipients (130+) from Gmail directly, existing addresses receive them.
But when I send emails to the same recipients using phpMailer, existing addresses also don't get emails.
Could this be because using phpMailer, emails can be only sent to 100 recipients at a time??
What could be the issue with phpMailer on this??