High-Throughput SMTP Relay API

Sub-Second Delivery, Unmatched Reliability

Whether you are sending verification codes, automated notifications, or programmatic marketing campaigns, our distributed SMTP relay infrastructure handles billions of monthly transactions with zero queuing bottlenecks.

• Standard SMTP protocols (Ports 25, 587, 465, 2525)
• Automated TLS 1.3 encryption on all transport layers
• Turnkey integration with PHP, Node.js, Python, Ruby, Go, and C#
• Automated SPF, DKIM signature stamping and DMARC alignment
• Dedicated IP pools available with custom warmup schedules

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host       = 'smtp.171mails.com';
$mail->SMTPAuth   = true;
$mail->Username   = 'your_api_key';
$mail->Password   = 'your_secret_token';
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
$mail->Port       = 587;

$mail->setFrom('hello@yourdomain.com', 'Your App');
$mail->addAddress('user@customer.com');
$mail->Subject = 'Your Order Confirmation';
$mail->Body    = 'Your order has shipped!';
$mail->send();