Reliable end‑to‑end testing for QA teams
Mailosaur gives QA teams a deterministic, isolated way to test message‑driven workflows with confidence.
Trusted by QA teams across every industry
Test email and SMS in one consistent workflow
Signup and onboarding journeys
Password reset flows
One-time passcodes, MFA and authentication paths
Transactional notifications and alerts
Deterministic tests without inbox collisions
Mailosaur provides unlimited email addresses, and test inboxes that can be used freely across environments, test runs, and team members.
Each test operates in isolation, eliminating shared state, race conditions, and flaky tests that undermine confidence in automation results.
Used by those in the know
This is the easiest solution to test your emails and I can show you how it works in 5 minutes.
Validate rendering without leaving your test workflow
Email previews in Mailosaur allow QA teams to inspect how emails render across real devices, email clients, and light or dark mode.
This makes it possible to validate layout and visual regressions alongside functional tests, instead of relying on screenshots or email service provider editors that don’t reflect real inbox behaviour.
Why Mailosaur?
Use your favorite framework
Mailosaur supports Cypress, Playwright, Selenium, Robot Framework, and more.
Manage team access per project
Our centralized system allows shared access for your entire team on a single account.
Compliant and secure
With comprehensive information security and GDPR-compliant controls, we are committed to protecting your data.
Trusted by QAs across the board
5.0
We have experimented with various tools for handling emails in test automation, particularly for OTPs and 2FA, and Mailosaur has consistently been the easiest to use—it just works.”
5.0
The one email platform for testing. I love Mailosaur as it allows me to create multiple inboxes with different domains but manage them all under one access and one view. [I also like] its capability to integrate with familiar test automation tools like Cypress and Playwright.
Built to integrate with real QA stacks
Mailosaur fits naturally into existing QA automation workflows.
Whether tests run locally or in CI, QA teams can send real emails or SMS from the application under test, fetch messages via API, and assert on content, links, verification codes, and timing.
// Step 1: Send an email into Mailosaur
// Step 2: Fetch your message via Mailosaur
const MailosaurClient = require('mailosaur');
const mailosaur = new MailosaurClient('YOUR_API_KEY');
const criteria = {
sentTo: 'anything@YOUR_SERVER_ID.mailosaur.net',
};
const email = await mailosaur.messages
.get(serverId, criteria);
// Step 3: Complete the process
expect(email.subject).toBe('My password reset');// Step 1: Send an email into Mailosaur
// Step 2: Fetch your message via Mailosaur
const MailosaurClient = require('mailosaur');
const mailosaur = new MailosaurClient('YOUR_API_KEY');
const criteria = {
sentTo: 'anything@YOUR_SERVER_ID.mailosaur.net',
};
const email = await mailosaur.messages
.get(serverId, criteria);
// Step 3: Complete the process
expect(email.subject).toBe('My password reset');How it works
Boost end-to-end test coverage in minutes, by integrating with Mailosaur.
Send an SMS message
Trigger a process in your product that sends out email or SMS (e.g. requesting a password reset).
Fetch the email from Mailosaur
Use one of our client libraries to pinpoint and pull the email down into your test code.
Complete the process
Check the content of the message, following a link or using a verification code.
Our products
Everything you need to test customer communication
Email testing
Create end-to-end tests that rely on email. Test account verification emails, password resets, email tracking and more.
Email previews
Instantly see how your email will look to any recipient, no matter what email client they use, so there are no nasty surprises.
SMS testing
Build text messages that work. Create end-to-end tests that cover identity verification, alerting, promotional messages, and more.
Test all user interactions
Test end-to-end scenarios, validate emails, and integrate with our API for seamless workflows.
Start your 14 day free trial today.