Skills Development Configure SMTP Mailer Settings

Configure SMTP Mailer Settings

v20260825
webiny-mailer-smtp
This guide details how to configure SMTP settings for email delivery within a Webiny project. By adding the `<Api.Mailer.Smtp />` component to your `webiny.config.tsx`, you can programmatically set the host, port, and credentials for email services. It emphasizes using environment variables for secure password handling and running the build command after any configuration changes.
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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/extensions";

<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/extensions";

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 v20260825
Size 3.88KB
Updated At 2026-09-06
Language