Fake SMTP servers
Catch staging emails in private MailSlurp inboxes before test messages can reach real users.
Use MailSlurp for private inbox APIs, device previews, email sandbox workflows, and CI automation across QA and engineering teams.

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Used by engineering, QA, lifecycle, and operations teams building and testing email and SMS workflows.

Catch staging emails in private MailSlurp inboxes before test messages can reach real users.
Use the virtual inbox API to cover signup, password reset, notification, and billing scenarios in your existing test stack.
Validate email HTML and CSS, then preview how supported web, mobile, and desktop contexts handle each template.
Use SMTP for quick integration or the Email API when tests need deeper control over inboxes, messages, and assertions.
Teams searching for a Mailtrap alternative usually need private inbox APIs, sandbox capture, deterministic waits, and release checks that run in CI.
| Criteria | Mailtrap | MailSlurp |
|---|---|---|
| Primary use case | SMTP sandbox and preview workflows | End-to-end send and receive testing with APIs |
| Inbox automation | Focus on sandbox and preview features | Programmatic inbox creation and cleanup |
| Template previews | Useful sandbox preview and inspection workflows | Device previews from the same message used for inbox, link, OTP, and release checks |
| SMS and OTP testing | Not primary product focus | Built-in SMS APIs and OTP workflow support |
| CI and framework support | Integrations for common stacks | SDKs and examples for Playwright, Cypress, Selenium, and more |
| Parser and extraction workflows | Typically requires additional tooling | Built-in parser and structured extraction APIs |
| Migration path to production workflows | Focused on sandbox testing | One platform for sandbox, automation, and production routes |
Teams replacing Mailtrap usually need more than preview inboxes: stable API assertions, private inbox isolation, and release gates for transactional email workflows.
MailSlurp routes each common Mailtrap-style job into a concrete testing workflow: email testing, SMTP capture, API automation, or framework-specific setup.
Use private inboxes to verify signups, password resets, transactional messages, and template content during QA.
Route staging SMTP traffic into controlled inboxes, then assert sender, subject, body, links, and attachments from tests.
Create inboxes, wait for matching emails, extract OTP codes, and clean up test data through API and SDK calls.
Use isolated inboxes for Laravel notification, Mailable, password reset, and invite flows without relying on shared preview mailboxes.
If you are switching from Mailtrap, follow these steps to keep QA moving and avoid breaking release checks during the changeover.
If you have multiple teams, regulated workflows, or high email volume, you will want clear ownership, repeatable checks, and a clean rollback plan.

Make sure your critical path is working. Test signups, password resets, and more with real email addresses.

Automate messaging workflows for your team. Use webhooks, forwarding, proxies, auto-replies, and routing rules to build powerful messaging workflows that integrate with your systems.

Use MailSlurp to test your email deliverability and reputation. Monitor your bounce rate and spam complaints.
No-code dashboards and developer integrations that let you test applications before they break, automate painful workflows, and avoid the dreaded spam folder.
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Configure auto-response, routing, and email forwarding rules. Create proxy email aliases to protect private addresses.
Get notified directly to your server when new emails arrive. Define pattern matching criteria and scale your email application.
Validate email addresses to improve customer deliverability and reduce spam. Verify bulk address lists or test emails in real time.
Specialized test methods that wait for matching email content. Integrates perfectly with end-to-end testing flows in Cypress, Selenium, Playwright and more.
Move from preview-only testing to end-to-end workflow validation. Start free and scale by API.
