Retrieve Stripe Customers via email

getStripeCustomersViaEmail.php

<?php 

$email = "your_email_query_here";

    try {
        $client = $client = new \GuzzleHttp\Client();
        $client->setDefaultOption('verify', true);

        $httpResource = 'https://api.stripe.com/v1/search?query="'.$email.'"&prefix=false';
        $request = $client->get($httpResource, [
            'headers' => ["Content-Type" => "application/x-www-form-urlencoded", "Authorization" => "Bearer ".$stripeApiKey]
        ]);
        $response = json_decode($request->getBody());
        if ($response->count > 0) {
            foreach ($response->data as $customer) {
               if (strlen($customer->id) == 18) {
                   echo $customer->id . PHP_EOL;
               } 
            }
        } else {
            return 'No match found';
        }


    } catch (ClientException $e) {
        if ($e->hasResponse()) {
            Log::info('ClientException: RequestService::get() =>' .print_r($email, true) . '=>' . $e->getMessage());
            return;
        }
    } catch (TransferException $e) {
        Log::info('TransferException: RequestService::get() =>' .print_r($email, true) . '=>' . $e->getMessage());
        return;
    }

using this will return every object related to this email, it's better to restrict the search by object type customer
so the URL:
$httpResource = 'https://api.stripe.com/v1/search?query=is:customer email:'.$email.'&prefix=false';