Fake SMTP server for testing emails

Setting up an email server for testing is usually associated with headaches. Lots of environments, difficult collaboration, a risk of sending emails to real users tend to produce a great mess.

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Debug Mail makes a developer’s life easier.

Create new team

Sign in to Debug Mail and create new team.

Invite colleagues

Share projects with your colleagues.

Create new project

Create new or choose existing project and open Project Settings page in context menu.

Setup SMTP connection

Setup SMTP connection in your development environment using values from this page.


  • Easy to setup

    Few simple steps and ready to work

    No SMTP required

    Start project without real SMTP server

  • Download emails

    Download email as a .EML file and open it in your desktop email client

    Forward email

    Forward the email to actual addresses

    Different email clients SOON

    Browsing emails in different email clients

  • Mail viewer

    View emails in different formats: HTML or plain text

    Open Source free

    Free for Open Source projects

    IMAP integration SOON

    IMAP server for integration purposes

  • Group emails

    Collect emails by a project

    Share projects

    Share projects with your colleagues

    Public links

    Share projects in public via the secret link

  • No spam SOON

    Do not spam real users

    Spam rating SOON

    Check your emails spam score

Setup Guide

Just copy following snippets to your app settings and change SMTP credentials to those that in your Debug Mail settings.

  • .NET

        <smtp from="john.doe@example.org">
          <network defaultCredetials="false"
            port="<project port>"
            userName="<project login>"
            password="<project password>"
            enableSsl="false" />
  • NodeJS

    var transporter =
      host: 'app.debugmail.io',
      port: 25,
      auth: {
        user: 'user@example.org',
        pass: '<project password>'
  • PHP

    return array(
        "driver" => "smtp",
        "host" => "app.debugmail.io",
        "port" => <project port>,
        "from" => array(
            "address" => "john.doe@example.org",
            "name" => "John Doe"
        "encryption" => "tls",
        "username" => <project login>,
        "password" => <project password>,
        "sendmail" => "/usr/sbin/sendmail -bs",
        "pretend" => false
  • PHP

    zend 2
    // Setup SMTP transport using LOGIN authentication
    $transport = new SmtpTransport();
    $options = new SmtpOptions(array(
        "name" => "debugmail",
        "host" => "app.debugmail.io",
        "port" => <project port>,
        "connection_class" => "plain",
        "connection_config" => array(
            "username" => <project login>,
            "password" => <project password>
  • Python

    EMAIL_HOST = "app.debugmail.io"
    EMAIL_HOST_USER = <project login>
    EMAIL_HOST_PASSWORD = <project password>
    EMAIL_PORT = <project port>
  • Python

    app.config["MAIL_PORT"] = 25
    app.config["MAIL_USERNAME"] = <project login>
    app.config["MAIL_PASSWORD"] = <project password>
    app.config["MAIL_USE_TLS"] = True
  • Ruby

    Ruby on Rails
    :address => "app.debugmail.io",
    :user_name => <project login>,
    :password => <project password>,
    :port => <project port>,
    :authentication => "plain",
    :enable_starttls_auto => true

Plans and pricing

We provide a free Silver plan for OSS projects. Contact us here to connect.

Free Silver Gold
Projects 1 10 Unlimited
Team Members 2 20 Unlimited
Test Emails per Day Unlimited Unlimited Unlimited
Forwarding Emails per Day 1 100 Unlimited
Mailbox Storage Limit 10MB per team 1GB per team 5GB per team
Forwarding Rules 1 per project 20 per project
IMAP Soon Soon
Spam Rating Soon
Mail Client Viewer Soon
Pricing $0
then $2
per user per month
per user per month

Our happy clients

Thousands of developers around the world already trust Debug Mail to keep their testing emails.



  • @debug_mail rules, fantastic tool.

    Ioannis Blougouras

    Net developer, node.js enthusiast.
  • @Having problems with mailcatcher? @debug_mail is a fantastic alternative! Using it tonight, after they favourited my tweet, brill marketing

    Jamie Hurst

    Lead developer of php, python, node, go and other things.
  • Testing email might be a bit more fun with @debug_mail, an easy to use mail server for developers and their teams.

    Brendon Kozlowski

    Php development.
  • What a great time saver. Debug Mail is an easy to use mail server for developers.


    The godfather of code.
  • Really nice and simple @debug_mail

    Jean-Francis AHANDA

    Head of Cloud & Managed services.
  • Starting to use @debug_mail more and more! So much quicker than setting up a mail catcher for capturing emails sent from a server.

    David Darke

    Co-founder and technical lead of @atomicsmash, a WordPress studio.
  • @debug_mail just wanted to say I really dig your guys’ product – slick interface!

    Jack Kingsman

    Development engineer and full stack developer.
  • @debug_mail that’s for the favourite. Looks like you have a useful product! I’ll investigate, cheers!

    Rob Gray

    Developer @sixpivot.
  • @debug_mail Really beautiful website. I love it

    Clément Houde

    CEO at Pixodeo.
  • debugmail.io прикольный, хорошо подходит для стейджингов всяких.

    Alex Balabanov

    Marketing Director at VIS.
  • Me ha venido fenomenal este servicio: debugmail.io.


  • For an efficient, simple, and completely free mail trapping service give DebugMail from @wbtech_live a go at debugmail.io. As an extra, it allows multiple and sharable mailboxes too.

    Kana Ki

    Kana Ki
  • Thanks for your reply and this great application.

    Demoustiez Sébastien

    Developer & Project Manager.
  • We’ve been using with great success of your services which is Debug Mail.

    Krzysztof Szromek

    Exlabs Software Ltd. CTO.
  • Thank you for your service!

    Elad Gasner

    CloseApp / Research & Development (R&D) Manager.
  • Your system is really nice and simple.

    Paolo Chianese

    Tayo Software / Chief Technology Officer.
  • We like to use debugmail.io.

    Bas van Engelen

    Kamer van Koophandel (KVK) / Information Analyst.
  • I am using debugmail for some time now and it’s incredibly handy.

    Marco Wettstein

    Panter / Senior Software Developer.
  • I’ve been using Debugmail for a few months, a great app.

    Matthieu Roy

    Utopix / CTO & Co-founder.
  • Debugmail is a great service.

    Nick Hammond

    Waracle / Senior Systems Engineer.
  • Thanks for letting us use such a great tool!

    Santiago Bermejo

    Redegal / Senior Magento Developer.

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