SMTP

Node.js

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.postal.so',
  port: 465,
  secure: true, // TLS direto; para a porta 587 use secure: false
  auth: {
    user: 'postal',
    pass: process.env.POSTAL_API_KEY,
  },
});

const info = await transporter.sendMail({
  from: 'Loja Exemplo <[email protected]>',
  to: '[email protected]',
  subject: 'Seu pedido #10482 saiu para entrega',
  html: '<p>O pedido <b>#10482</b> está a caminho.</p>',
});

console.log(info.response); // 250 2.0.0 OK queued as 019a1b2c-...

Python

import os
import smtplib
from email.message import EmailMessage

message = EmailMessage()
message["From"] = "Loja Exemplo <[email protected]>"
message["To"] = "[email protected]"
message["Subject"] = "Seu pedido #10482 saiu para entrega"
message.set_content("O pedido #10482 está a caminho.")
message.add_alternative("<p>O pedido <b>#10482</b> está a caminho.</p>", subtype="html")

with smtplib.SMTP_SSL("smtp.postal.so", 465) as server:
    server.login("postal", os.environ["POSTAL_API_KEY"])
    server.send_message(message)

PHP

use PHPMailer\PHPMailer\PHPMailer;

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host = 'smtp.postal.so';
$mail->Port = 465;
$mail->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS; // 587: ENCRYPTION_STARTTLS
$mail->SMTPAuth = true;
$mail->Username = 'postal';
$mail->Password = getenv('POSTAL_API_KEY');
$mail->CharSet = 'UTF-8';

$mail->setFrom('[email protected]', 'Loja Exemplo');
$mail->addAddress('[email protected]');
$mail->Subject = 'Seu pedido #10482 saiu para entrega';
$mail->isHTML(true);
$mail->Body = '<p>O pedido <b>#10482</b> está a caminho.</p>';
$mail->send();

Laravel

# .env
MAIL_MAILER=smtp
MAIL_SCHEME=smtps
MAIL_HOST=smtp.postal.so
MAIL_PORT=465
MAIL_USERNAME=postal
MAIL_PASSWORD=ps_sua_chave
[email protected]
MAIL_FROM_NAME="Loja Exemplo"

cURL

curl --ssl-reqd --url "smtps://smtp.postal.so:465" \
  --user "postal:$POSTAL_API_KEY" \
  --mail-from "[email protected]" \
  --mail-rcpt "[email protected]" \
  --upload-file message.eml