Email & SMS testing for any app, product or campaign
Improve quality and increase confidence with the number one customer communication testing platform.

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!

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
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.
Learn more
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.
Learn moreDesigned for Automation
Automate email & SMS tests with any framework
Automate email and SMS testing with Mailosaur, whether you're working with Cypress, Selenium, Webdriver.io, 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 DocsHere to get you started
We have engineers on hand to help you get your proof of concept up and running in minutes.
Get in Touch
// 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: 'someone@SERVER_ID.mailosaur.net'
});
// 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.
Forwarding
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
AWeber
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