nodemailer with mailhog using docker

Question

Trying to send mail using nodemailer, got "outside" as an answer (means mail was not sent). No error, or anything that can be catched

index.js

app.get('/test', async (req, res) => {

  const email = require("./core/email");
  var mail = new email();
  var msg = await mail.sendMail();

  res.send(`${msg}`);
})

email.js

var nodemailer = require('nodemailer');

class email {
  transporter;
  mailOptions;

  constructor() {
    this.transporter = nodemailer.createTransport({
      port: 1025,
    });

    this.mailOptions = {
      from: '[email protected]',
      to: '[email protected]',
      subject: 'Confirm Email',
      text: 'Please confirm your email',
      html: '<p>Please confirm your email</p>'
    };

  }

   async sendMail() {
    await this.transporter.sendMail(this.mailOptions, (error) => {
      if (error) {
          return error;
      }
      return 'Sent:';
    });
    return 'outside';
  }

}

module.exports = email;

docker-compose.yml

version: "3"
services:
  mailhog:
    image: mailhog/mailhog
    ports:
      - 1025:1025 # smtp server
      - 8025:8025 # web ui

docker ps shows mailhog container, and web UI works fine in http://localhost:8025/

CONTAINER ID   IMAGE                     COMMAND                  CREATED        STATUS        PORTS                                            NAMES
f437dd5c7f09   test_test-app             "docker-entrypoint.s…"   16 hours ago   Up 16 hours   0.0.0.0:3000->3000/tcp                           test_test-app_1
d1c3f6ca1a6a   mailhog/mailhog           "MailHog"                16 hours ago   Up 16 hours   0.0.0.0:1025->1025/tcp, 0.0.0.0:8025->8025/tcp   test_mailhog_1
2ff9a562c344   mongo                     "docker-entrypoint.s…"   16 hours ago   Up 16 hours   27017/tcp                                        test_mongo_1

Answer 1

Make sure to add the host, the host should be the docker service name stated in the docker-compose file.

this.transporter = nodemailer.createTransport({
  host: 'mailhog',
  port: 1025,
});

docker-compose file:

    mailhog:
       image: mailhog/mailhog
       ports:
         - 1025:1025 # smtp server
         - 8025:8025 # web ui