Skills Development Configure SMTP Mailer Settings in Webiny

Configure SMTP Mailer Settings in Webiny

v20260507
webiny-mailer-smtp
This guide details how to configure SMTP email delivery settings within a Webiny project using the `<Api.Mailer.Smtp />` component. It specifies the required properties (host, port, user, etc.) and emphasizes best practices, such as passing sensitive passwords via environment variables rather than hard-coding them. Ideal for developers setting up external email services.
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Overview

Mailer SMTP Configuration

TL;DR

Add <Api.Mailer.Smtp ... /> to your webiny.config.tsx to configure SMTP email delivery at build time. The component serializes the settings into the build artifact — always pass the password via an environment variable, never hard-code it. Deploy the API after making changes.

Core Pattern

import { Api } from "@webiny/project-aws/api";

<Api.Mailer.Smtp
    host={"smtp.example.com"}
    port={587}
    user={"smtp-user"}
    password={process.env.SMTP_PASSWORD!}
    from={"noreply@example.com"}
    replyTo={"support@example.com"}   {/* optional */}
/>

Place this inside the JSX returned by your config component in webiny.config.tsx, alongside other <Api.*> extensions.

Props Reference

Prop Type Required Description
host string Yes SMTP server hostname
port number Yes SMTP server port (positive integer)
user string Yes SMTP authentication username
password string Yes SMTP authentication password — use env var
from string Yes Default sender address
replyTo string No Default reply-to address

from and replyTo are validated by the email-addresses package against RFC 5322.

Full Example (webiny.config.tsx)

import React from "react";
import { Api, Admin, Core } from "@webiny/project-aws/api";

const MyConfig = () => {
  return (
    <>
      {/* ... other extensions ... */}

      {/* Mailer: configure SMTP transport via code */}
      <Api.Mailer.Smtp
        host={"smtp.sendgrid.net"}
        port={587}
        user={"apikey"}
        password={process.env.SENDGRID_API_KEY!}
        from={"noreply@acme.com"}
        replyTo={"support@acme.com"}
      />
    </>
  );
};

Add SENDGRID_API_KEY=your-secret to your .env file (never commit it).

Common Mistakes

Mistake Fix
Hard-coding the password Use process.env.SMTP_PASSWORD!
process.env.SMTP_PASSWORD undefined at build time → "expected string, received object" error Ensure the env var is set before deploying
from/replyTo value fails validation Must be a valid RFC 5322 mailbox address
Settings not taking effect Run yarn webiny build api after editing webiny.config.tsx

Quick Reference

# After editing webiny.config.tsx, build the API
yarn webiny build api

Note: This command only works in a dev environment. For other environments, run yarn webiny build api --env=YOUR_ENV instead.

// Environment variable in .env
SMTP_PASSWORD = your - smtp - password - here;

Related Skills

  • webiny-project-structure — Where webiny.config.tsx lives and how extensions are structured
  • webiny-local-development — Running and deploying locally
Info
Category Development
Name webiny-mailer-smtp
Version v20260507
Size 3.89KB
Updated At 2026-05-08
Language