Mailpit

Mailpit catches all outgoing emails from your app and shows them in a browser UI. Your app sends email normally — Mailpit intercepts it instead of delivering it. No real emails are ever sent.

devstack add mailpit

Options

Flag	Default	Description
-p, --smtp-port	1025	SMTP port your app sends to
-u, --ui-port	8025	Web UI port to inspect emails

Open the inbox

devstack open mailpit

Opens http://localhost:8025 where you can read every email your app sends.

Application config examples

Point your app's mailer at localhost:1025 with no authentication:

.env

MAIL_HOST=localhost
MAIL_PORT=1025
MAIL_FROM=noreply@devstack.local

TypeScript (Nodemailer)

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'localhost',
  port: 1025,
  secure: false,
  ignoreTLS: true,
});

await transporter.sendMail({
  from: 'noreply@devstack.local',
  to: 'user@example.com',
  subject: 'Hello',
  text: 'This appears in Mailpit, not in anyone\'s inbox.',
});

Python (smtplib)

import smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg['From'] = 'noreply@devstack.local'
msg['To'] = 'user@example.com'
msg['Subject'] = 'Hello'
msg.set_content('This appears in Mailpit.')

with smtplib.SMTP('localhost', 1025) as smtp:
    smtp.send_message(msg)

:::info No auth needed Mailpit accepts any SMTP connection without authentication. You don't need to set a username or password in your mailer config. :::