Send email with Mailgun via cURL

mailgun.php

function mailgun($message = null, $to = null)
{
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_setopt($ch, CURLOPT_USERPWD, 'api:key-abc');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

    $plain = strip_tags($message);

    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
    curl_setopt($ch, CURLOPT_URL, 'https://api.mailgun.net/v3/DOMAIN-abc/messages');
    curl_setopt($ch, CURLOPT_POSTFIELDS, array('from' => 'Joe Bloggs <person@example.com>',
        'to' => $to,
        'subject' => 'Subject line',
        'html' => $message,
        'text' => $plain));

    $j = json_decode(curl_exec($ch));

    $info = curl_getinfo($ch);

    if ($info['http_code'] != 200){
          echo "Email could not be sent";
          exit;
    }

  curl_close($ch);

  return $j;

}