[ 'user1@example.com', 'user2@example.com', 'user3@example.com' ], 'subject' => 'Monthly Newsletter', 'content' => '

Newsletter

Here are the latest updates...

', 'eds_id' => 1, 'footer_id' => 1, 'params' => [] ]; curl_setopt_array($curl, [ CURLOPT_URL => 'https://api.campaignrefinery.com/api/send/bulk_email', CURLOPT_RETURNTRANSFER => true, CURLOPT_ENCODING => '', CURLOPT_MAXREDIRS => 10, CURLOPT_TIMEOUT => 30, CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1, CURLOPT_CUSTOMREQUEST => 'POST', CURLOPT_POSTFIELDS => json_encode($data), CURLOPT_HTTPHEADER => [ 'Content-Type: application/json', 'Key: YOUR_API_KEY' ], ]); $response = curl_exec($curl); $err = curl_error($curl); curl_close($curl); if ($err) { echo 'cURL Error #:' . $err; } else { echo $response; }