Email & SMS testing for any app, product or campaign

Improve quality and increase confidence with the number one customer communication testing platform.

Test email and SMS with Mailosaur Uber AWeber GoodRx Starbucks

Email Testing

Create catch-all email servers, with an infinite set of email addresses, check account verification, password resets, marketing announcements and offers! All smoothly integrated with your existing test framework.

SMS Testing

If your business sends text message notifications or simply use SMS for identity verification, you can create end-to-end test coverage using phone numbers from around the world.

Email Previews

See what your emails really look like. With Mailosaur you can generate screenshots in real-time on everything from Microsoft Outlook and IBM Notes on PC, to Apple Mail on iPhone and GMail on Android.

Build and test products that work!

Whether you're doing some exploratory testing, or plan to create a fully automated end-to-end test suite, Mailosaur will help you raise the quality bar!

SMS Test

Email and SMS testing API

Fetch, reply and forward email and SMS messages using a simple API, with official clients for all major languages and testing frameworks.

Create automated end-to-end tests to cover every aspect of your product or campaign.

Read the docs
SMS Test

Deliverability and Email Analysis Tools

Maximise the number of emails reaching your customers by letting our email analysis tools do the hard work and highlight any deliverability issues.

Create the perfect email, free of technical issues by using our issues reports.

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SMS Test

Simulate real customer interactions

Customers can communicate in many ways with your applications including email and SMS. You want to make sure that these interactions keep working.

With Mailosaur you can simulate real-world scenarios, with phone numbers and email addresses that let you perform end-to-end tests of critical workflows.

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Designed for Automation

Automate email & SMS tests with any framework

Automate email and SMS testing with Mailosaur, whether you're working with Cypress, Selenium,, Robot Framework or anything else...

Tools for any language

We offer client libraries for everything from Node.js, Java and Python to plugins for frameworks like Cypress.

Read the Docs

Here to get you started

We have engineers on hand to help you get your proof of concept up and running in minutes.

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// Initialize Mailosaur
const MailosaurClient = require('mailosaur');
const mailosaur = new MailosaurClient('YOUR_API_KEY');

(async () => {
  // Fetch an email
  const email = await mailosaur.messages.get('SERVER_ID', {
    sentTo: ''

  // Do some assertions
  assert.equal(email.subject, 'Password reset request');

Take a look at our features

Solutions for every testing scenario

Email Testing

Automate email tests, like account verification and password resets.

SMS Testing

Test processes such as multi-factor SMS authentication or text message notifications.

Client Libraries

Get started in seconds with Cypress, Playwright, Selenium or any other language or test framework.

Unlimited email addresses

An infinite number of instantly available email addresses for every test run or suite.

Follow links and verification codes

Grab links and follow them like a customer would, trigger tracking beacons or pull verification codes from email or SMS.

Virtual SMTP Servers

Catch every email on your development and staging environments, so they never reach a customer.

Message viewer

Manually test messages in an easily-searchable web client, specifically designed for email & SMS testing.


Automatically forward emails to your regular mail client via easy to customise rules.

Sending & Replying

Emulate real user interactions, by sending or replying to emails.

Set your own email domain

Create easily identifiable email addresses for each test run or suite.

Spam Analysis

Improve email quality and deliverability by lowering your spam score.

POP3 Support

Access your test email on any mail client, whether on a laptop, tablet or phone, via POP3.

Single Sign-On

Meet your company's compliance obligations by authenticating using SAML or OpenID Connect providers (e.g. Okta).

Security & Trust

With comprehensive Information Security and GDPR-compliant controls, we protect your data and the data of your customers.

If you need a tool with a clean API to test emails you send, Mailosaur gives you everything you need for a low monthly price.

QA Automation Engineer


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