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Developer command center for sending important email.

Start with an API key, verify a domain, send through API or SMTP, then use events and logs to debug OTPs, invoices, alerts, and product email in production.

Start free Quick start

Quick start Domain setup API reference Troubleshooting

Quick start

Send your first email.

Choose API code if you are integrating from scratch, or keep SMTP if your app already sends mail that way.

curl -X POST https://api.whyemails.com/v1/send \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your-api-key-here" \
  -d '{
    "to": "recipient@example.com",
    "from": "your@verified-domain.com",
    "subject": "Test Email",
    "body": "This is a test email."
  }'

$client = new \GuzzleHttp\Client();
$response = $client->request('POST', 'https://api.whyemails.com/v1/send', [
    'headers' => [
        'X-API-Key'    => 'your-api-key-here',
        'Content-Type' => 'application/json',
    ],
    'json' => [
        'to'      => 'recipient@example.com',
        'from'    => 'your@verified-domain.com',
        'subject' => 'Test Email',
        'body'    => 'This is a test email.',
    ],
]);

import requests

response = requests.post(
    "https://api.whyemails.com/v1/send",
    headers={
        "Content-Type": "application/json",
        "X-API-Key": "your-api-key-here",
    },
    json={
        "to": "recipient@example.com",
        "from": "your@verified-domain.com",
        "subject": "Test Email",
        "body": "This is a test email.",
    },
)
print(response.status_code, response.text)

const response = await fetch("https://api.whyemails.com/v1/send", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "X-API-Key": "your-api-key-here"
  },
  body: JSON.stringify({
    to: "recipient@example.com",
    from: "your@verified-domain.com",
    subject: "Test Email",
    body: "This is a test email."
  })
});

console.log(await response.json());

Replace from with an address on a verified sending domain.

Domain setup

SPF

Authorize WhyEmails to send mail for your domain.

DKIM

Sign each message so receiving servers can verify it.

DMARC

Align sender identity and review your policy before full production traffic.

API reference

Send emailPOST

https://api.whyemails.com/v1/send

toRecipient email address

fromSender address on a verified domain

subjectEmail subject line

bodyEmail body content, HTML supported

Troubleshooting

Domain not verified

Check DNS propagation, record values, and the sender domain you are using.

Temporary deferral

Inspect retry state and the receiving server response before resending manually.

Webhook failure

Review endpoint response codes and webhook retry history.