PHP

cURL（无依赖）

send.php

<?php
function spacepost_send(array $email, ?string $idempotencyKey = null): array {
    $headers = [
        'Authorization: Bearer ' . getenv('SPACEPOST_API_KEY'),
        'Content-Type: application/json',
    ];
    if ($idempotencyKey) {
        $headers[] = 'Idempotency-Key: ' . $idempotencyKey;
    }
    $ch = curl_init('https://api.spacepost.dev/emails');
    curl_setopt_array($ch, [
        CURLOPT_POST => true,
        CURLOPT_HTTPHEADER => $headers,
        CURLOPT_POSTFIELDS => json_encode($email),
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 15,
    ]);
    $body = json_decode(curl_exec($ch), true);
    $status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
    curl_close($ch);
    if ($status >= 300) {
        throw new RuntimeException("{$body['name']}: {$body['message']}");
    }
    return $body; // ['id' => '...']
}

print_r(spacepost_send([
    'from' => 'Acme <hello@acme.com>',
    'to' => ['delivered@test.spacepost.dev'],
    'subject' => 'Hello from PHP',
    'html' => '<p>It works.</p>',
]));

Guzzle

composer require guzzlehttp/guzzle

send.php

<?php
require 'vendor/autoload.php';

$client = new GuzzleHttp\Client([
    'base_uri' => 'https://api.spacepost.dev',
    'headers' => ['Authorization' => 'Bearer ' . getenv('SPACEPOST_API_KEY')],
    'http_errors' => false,
    'timeout' => 15,
]);

$res = $client->post('/emails', ['json' => [
    'from' => 'Acme <hello@acme.com>',
    'to' => ['delivered@test.spacepost.dev'],
    'subject' => 'Hello from Guzzle',
    'html' => '<p>It works.</p>',
]]);

echo $res->getStatusCode(), ' ', $res->getBody();

使用 Laravel？SMTP 中继无需修改代码。