Disposable inboxes
Per test run
Generate a unique email address per suite or per spec for isolation and parallel safety.
Test OTP codes and magic links in Cypress with real inboxes
MailSlurp gives QA teams disposable inboxes and deterministic wait helpers so Cypress suites can verify sign-up, password reset, and MFA email steps without shared mailboxes or flaky sleeps.
Works with your QA stack
Trusted by teams at
Used by engineering, QA, lifecycle, and operations teams building and testing email and SMS workflows.
Deterministic waits
No flaky sleeps
Wait for matching emails, then extract links or OTP codes reliably in CI.
HTML + attachments
Full payload
Assert on body content, headers, and attachments so the full customer-visible message is covered.
CI-friendly
Scale coverage
Run tests across multiple workers without mailbox collisions or manual cleanup.
Core capabilities
What teams need when email workflows matter
Create isolated inboxes per workflow and environment
Provision real inboxes on demand so each Cypress run has clean test data and predictable routing.
- Disposable inboxes
- Parallel-safe
- Clean fixtures
Wait for emails and extract OTP codes or magic links
Use wait helpers to find the right email, then parse links and codes to complete auth flows end-to-end.
- OTP codes
- Magic links
- Password reset
Assert on HTML, attachments, and headers
Validate the content customers actually see and ensure templates render, links work, and attachments are delivered.
- HTML parsing
- Attachments
- Header checks
Ship stable email tests in CI
Remove shared mailbox contention and flaky timing issues so failures are actionable and reproducible.
- CI
- Run evidence
- Faster debugging
Team use cases
How engineering, QA, and operations teams use MailSlurp
QA automation engineers
Verify sign-up and onboarding emails in Cypress
Test the highest-impact flows end-to-end with real inboxes and deterministic assertions.
- Capture verification links and OTP codes
- Reduce flakiness caused by timing and shared mailboxes
- Prove the customer journey is working before release
Platform and DevEx teams
Standardize email test helpers across squads
Create reusable Cypress patterns for inbox provisioning, waits, and content validation.
- Enable parallel test runs without collisions
- Reduce copy/paste test glue across repos
- Create a shared playbook for debugging failures
Release managers
Gate releases on critical email workflows
Convert manual spot checks into automated regression gates that run on every deployment.
- Catch broken templates before customers do
- Shorten incident response with clear evidence
- Increase confidence in staged releases
Getting started
Get this working quickly, then build on it
Day 1
Add one inbox assertion to a critical test
Start with the highest-impact workflow (sign-up, reset, or MFA) and validate email receipt plus one key assertion.
- Create a disposable inbox during the spec run
- Trigger a real workflow email from the app
- Wait for the email and extract the code or link
Week 1
Expand coverage and make it parallel-safe
Turn the first workflow into a repeatable pattern across specs and CI workers.
- Provision inboxes per worker to avoid collisions
- Store evidence (payloads and links) on failure
- Add assertions for HTML, headers, and attachments
Week 2+
Standardize and scale to multiple teams
Roll the pattern out to more workflows as coverage expands.
- Create shared Cypress helpers for inbox and wait logic
- Add monitoring around workflow failures
- Upgrade for higher volume, retention, and team access
Team fit
How different teams get value
QA teams shipping weekly
Challenge: Email steps break quietly and manual verification does not scale with release cadence.
What improves: Automate email assertions inside Cypress so regressions are caught before deploy.
Teams running parallel CI
Challenge: Shared inboxes and time-based sleeps cause flaky tests and non-deterministic failures.
What improves: Use disposable inboxes and deterministic waits to keep suites reliable under load.
Enterprise release stakeholders
Challenge: Production incidents happen when critical messaging workflows are not gated with evidence.
What improves: Turn email workflows into regression gates with clear payload evidence.
Customer outcomes
What gets better once MailSlurp is in place
Fewer flaky failures
Replace sleeps and shared mailboxes with deterministic inbox waits and isolation.
Faster debugging
Inspect the full email payload, links, headers, and attachments when tests fail.
Parallel-safe by design
Run many Cypress workers without mailbox collisions or fragile cleanup logic.
Clear upgrade path
Start free, then scale volume, reporting, and team access as coverage expands.
Ready to try this with your own workflow?
FAQ
Questions people ask before they start
Do you support Cypress Cloud or parallel CI workers?
Yes. Provision inboxes per worker or per run so messages never collide across parallel builds.
Can we test password reset and account verification flows?
Yes. Teams commonly assert on OTP codes, magic links, and reset links in sign-up and auth workflows.
Can we parse HTML and download attachments?
Yes. You can fetch HTML/text bodies, headers, and attachments to validate real customer content.
Is this only for JavaScript?
MailSlurp supports multiple SDKs and languages. Cypress users typically start with JavaScript or TypeScript.