sesmtp

Amazon SES transport over its SMTP interface, built on smtp-kit.

approvals.me

sesmtp adapts smtp-kit's injectable SMTP adapter to Amazon SES's SMTP interface: no AWS SDK, node:net/node:tls only.

Install

npm i sesmtp

import { createMailMessage } from "mailmessage";
import { createSesTransport } from "sesmtp";

const transport = createSesTransport({
  region: "eu-west-1",
  username: process.env.SES_SMTP_USERNAME!,
  password: process.env.SES_SMTP_PASSWORD!,
  from: "[email protected]",
  configurationSet: process.env.SES_CONFIGURATION_SET,
});

await transport.send({
  message: createMailMessage({
    from: "[email protected]",
    to: ["[email protected]"],
    subject: "Hello",
    text: "Sent through SES SMTP.",
  }),
});

Environment

| Variable | Default | Notes | | --- | --- | --- | | SES_REGION | eu-west-1 | Selects email-smtp.<region>.amazonaws.com. | | SES_SMTP_USERNAME | — | SES SMTP username, not an AWS access key. | | SES_SMTP_PASSWORD | — | SES SMTP password, not an AWS secret key. | | SES_CONFIGURATION_SET | — | Optional; sets X-SES-CONFIGURATION-SET. | | AUTH_EMAIL_FROM | [email protected] | Envelope/header default sender. | | AUTH_EMAIL_REPLY_TO | — | Optional default Reply-To. |

Connects to email-smtp.<region>.amazonaws.com:587 with STARTTLS by default (465/2465 use implicit TLS instead).

SES SMTP credentials come from the SES console under SMTP settings → Create SMTP credentials. They are a separate IAM user's SMTP username/password, generated specifically for this purpose — they are not your AWS access key ID and secret access key, which do not work over SMTP AUTH.

Non-goals

Connection pooling, retries, queues, and the AWS SDK are out of scope; a fresh connection is dialed per send (ponytail: single-flight dial, add pooling if SES throughput requires it).

MIT.