feathers-mailer

Feathers mailer service using nodemailer

npm install feathers-mailer nodemailer

nodemailer is a peer dependency, so you install it yourself and stay in control of its version.

If using a transport plugin, install the respective module.

Note: feathers-mailer@5 is ESM only and requires nodemailer@^10 and Node.js 22.18+. See Migration below.

import { Service } from 'feathers-mailer'

app.use('emails', new Service(transport, defaults))

• transport can be either SMTP options or a transport plugin with associated options.
• defaults is an object that defines default values for mail options.

service.create is a thin wrapper for transporter.sendMail, accepting body and returning a promise.

See here for possible fields of body.

import { Service } from 'feathers-mailer'
import nodemailer from 'nodemailer'

;(async function (app) {
  const account = await nodemailer.createTestAccount() // internet required

  const transporter = {
    host: account.smtp.host,
    port: account.smtp.port,
    secure: account.smtp.secure, // 487 only
    requireTLS: true,
    auth: {
      user: account.user, // generated ethereal user
      pass: account.pass, // generated ethereal password
    },
  }

  // Register service and setting default From Email
  app.use('mailer', new Service(transporter, { from: account.user }))

  // Use the service
  const email = {
    to: 'president@mars.com',
    subject: 'SMTP test',
    html: 'This is the email body',
  }

  const info = await app.service('mailer').create(email)
  console.log(`Preview URL: ${nodemailer.getTestMessageUrl(info)}`)
})(app)

import { Service } from 'feathers-mailer'
import mandrill from 'nodemailer-mandrill-transport'

// Register the service, see below for an example
app.use(
  '/mailer',
  new Service(
    mandrill({
      auth: {
        apiKey: process.env.MANDRILL_API_KEY,
      },
    }),
  ),
)

// Use the service
const email = {
  from: 'FROM_EMAIL',
  to: 'TO_EMAIL',
  subject: 'Mandrill test',
  html: 'This is the email body',
}

app
  .service('mailer')
  .create(email)
  .then(function (result) {
    console.log('Sent email', result)
  })
  .catch((err) => {
    console.log(err)
  })

A more and more appearing 'issue' these days, is that mail sent can be seen as spam. Especially if the 'from address' is not linked to the IP of the sending host. To prevent this, you can use a DKIM record. It does require a DNS mutation on the domain reflecting the 'from address', but it will prevent this. Following these steps you can implement this in node-mailer

1. Go to https://easydmarc.com/tools/DKIM-record-generator to generate a DKIM record. In the form, enter the domain name (equal to the from address domain), and something to use as a selector e.g. feathersMailer.
2. Ask a network administrator to publish the record which is generated in the domain.
3. Ensure the record is active using https://easydmarc.com/tools/dkim-lookup. Once the test passes, continue (it might need time to replicate across the web)
4. Add the following information to the email constance defined in the example above, so it becomes like this

const email = {
  to: 'president@mars.com',
  subject: 'SMTP test',
  html: 'This is the email body',
  domainName: 'THE DOMAIN ENTERED FOR THE RECORD (FROM ADDRESS DOMAIN)',
  keySelector: 'THE SELECTOR YOU ENTERED TO GENERATE THE RECORD',
  privateKey:
    'THE CONTENT FROM THE `PRIVATE KEY` BUT REPLACE `linebreaks` WITH `\n`',
}

Important: You must replace the linebreaks of the private key with \n or it won't work.

A use case for this, could be a multitenancy application. There the reply domains would be different, but you might want to send from the local SMTP server of the ISP. You would then make it possible for each tenant to configure the three values in their tenant settings within the application, and dynamically collect it prior to sending the mail.

v5 is a maintenance-only modernization - Service and service.create behave exactly as before. The breaking changes are all in packaging and types:

• ESM only. The CommonJS build is gone. require('feathers-mailer') no longer works; use import (or a dynamic import() from CJS).

• nodemailer@^10 is now an (optional) peer dependency instead of a direct dependency, so you install and pin it yourself.

• @types/nodemailer is no longer needed. nodemailer@10 ships its own types, including createTransport overloads.

• Transport classes are no longer re-exported as namespaces. The old SMTPTransport.Options style is gone, because nodemailer@10 drops those namespaces. Import the option types directly instead - feathers-mailer re-exports everything nodemailer exports:

  // before
  import type { SMTPTransport } from 'feathers-mailer'
  type Options = SMTPTransport.Options
  
  // after
  import type { SMTPTransportOptions } from 'feathers-mailer'

• The Service type parameter for defaults was dropped. nodemailer@10 types defaults uniformly as MailDefaults, so Service<Transport> takes a single type argument.

• Node.js 22.18+ is required.

Copyright (c) 2026

Licensed under the MIT license.