Mailinator

Mailinator provides temporary inboxes and tools for testing email and SMS workflows. Developers, QA teams, and businesses can use it to check delivery for OTP, MFA, onboarding, password recovery, and other email processes at scale. Subscriptions include private testing domains, where any address can receive test email without creating an inbox in advance. The REST API supports inbox and message retrieval, SMS retrieval, message injection, and CI/CD pipeline integration. Inbound webhooks can receive HTTP POST messages from sources such as alert systems, Zapier, or Twilio, then apply configured rules. SMS can be directed to an inbox or API for automated OTP and 2FA testing. Public inbox messages are readable by anyone and typically delete after several hours, so they should not be treated as private. Mailinator is receive-only: it cannot send email or fill out forms. The free public option requires no sign-up. Business costs $79 a month, billed yearly, and a free two-week Business trial is listed. The site says private system email bodies are encrypted at rest, while public system email is not; web traffic is served over HTTPS.

Mailinator offers temporary public inboxes and subscription-based private testing domains, with API and webhook tools for automated workflows. Keep in mind that public inboxes are open to anyone and the service cannot send email.

Mailinator suits developers and QA teams checking email and SMS workflows, including automated tests. Businesses can use its API, webhooks, and private domains for testing workflows at scale.

Mailinator is built for developers, QA teams, and businesses that need to verify incoming email and SMS workflows repeatedly. It is a strong fit for automated receipt checks and disposable testing addresses, but a poor choice when testing must include sending messages, form submission, or private data in public inboxes.

Overview

Founded in 2003 and headquartered in Ann Arbor, Michigan, Mailinator combines temporary public inboxes with subscription private testing domains. A private-domain address can receive test mail without being created first, which is useful for generating large numbers of onboarding, password-reset, OTP, and MFA scenarios. Public inboxes are available without sign-up, but anyone can read their messages and they generally disappear after several hours. Treat them as disposable test channels, not confidential storage.

Mailinator is receive-only: it cannot send email or fill out forms. That makes it effective for confirming delivery and parsing incoming content, but unsuitable for validating the outbound side of a complete account journey. Web traffic is served over HTTPS; private-system email bodies are encrypted at rest, while public-system email is not.

Key features

Email, SMS, and automation

The REST API retrieves inboxes, email, and SMS, supports message injection, and connects to CI/CD pipelines. Teams can route SMS to an inbox or API for automated OTP and two-factor checks. Inbound webhooks accept HTTP POST messages from alert systems, Zapier, or Twilio and apply configured rules, giving engineering teams a practical way to turn incoming events into repeatable tests.

SMS numbers cost $500 per number per year or $50 per month, including 500 messages monthly. That is useful for a defined verification program, but the per-number charge makes broad, always-on coverage expensive.

Operational and security considerations

Documentation is provided 24/7/365. Public issue emails are usually answered within 24–72 hours, while subscribers receive priority support. Hosting certifications listed for its providers include Linode SOC 1 Type 2, SOC 2 Type 2, HIPAA Type 1, HITECH, and PCI DSS, plus DigitalOcean SOC 2 Type 2, SOC 3 Type 2, and PCI DSS. These attestations help enterprise review, but they do not make public inbox content private.

Pricing

The free Public plan costs $0 and provides unlimited public inboxes, temporary storage, and no sign-up requirement. It is appropriate for quick, non-sensitive checks; shared visibility and short retention make it unsuitable for protected test data.

Verified Pro is $0.00 per free, billed with Verification. It includes unlimited private inboxes, one private domain, 10MB permanent storage, throughput of up to 10 emails per second, 2,000 emails per month and 60 per day annually, and one user. It adds privacy at no subscription cost but is tightly capped for volume and collaboration.

Business costs $79.00 per month, billed yearly, and includes unlimited private inboxes, one private domain, 50MB permanent storage, up to 20 emails per second, 100,000 emails per month, 3,333 per day, and five team seats. This is the sensible starting point for a small QA group that needs sustained private testing.

Business Plus is $159.00 per month, billed yearly. It raises the allowance to three private domains, 100MB storage, 100 emails per second, 300,000 emails per month, 10,000 per day, and 10 seats. Choose it when several products or teams need independent domains and higher concurrency.

Enterprise is $699.00 per contact with custom pricing. It provides five or more private domains, custom storage, up to 500 emails per second, 3MM+ emails per month, and custom daily limits and team seats. A two-week free Business trial is available before committing.

Platforms

Mailinator is offered through the web and an API. The API orientation matters most to teams wiring message checks into automated builds rather than manually inspecting inboxes.

Who it's for

Choose Mailinator for developers and QA teams testing receipt, OTP, MFA, onboarding, and recovery flows at scale, especially when private-domain addresses and CI/CD integration remove inbox-provisioning work. It also suits businesses that need webhook-fed workflow checks. Look elsewhere if you need outbound email, form automation, or confidentiality in a shared public inbox.

Pros and cons

• Pro: Private domains accept mail at uncreated addresses, simplifying high-volume and parameterized tests.
• Pro: API, message injection, SMS retrieval, and webhooks support automated pipelines and event-driven checks.
• Pro: Business tiers provide clear throughput, volume, domain, and seat expansion.
• Con: Public inboxes are readable by anyone and public-system email is not encrypted.
• Con: Receive-only operation cannot validate sending or form completion.
• Con: SMS testing adds $500 per number annually or $50 monthly, even with a 500-message allowance.

Alternatives

For a broader directory of testing tools, see Email Testing Software. Readers focused on disposable addresses can compare Disposable Email Services or Temporary Email Services.

Twilio Segment is a web, iOS, and Android freemium platform with a free tier for 1,000 visitors per month and 500,000 Reverse ETL records, so it fits customer-data activation rather than inbox receipt testing.

Emailens offers API, extension, and web access with 30 simulated previews per day on its free plan; pick it for client-rendering previews instead of message workflow testing.

EmailQA provides real-device email renders, projects, and guest reviewers, making it the better choice for visual QA across devices.

Mailpit is free, self-hosted, and distributed as a binary or Docker image; choose it when local infrastructure and simple retention matter more than hosted private domains.

MailSlurp combines API and web inboxes with a free allowance for received emails, sandbox sends, renders, and inbox creation; consider it when limited sending and rendering are required.

Mailtrap Email Sandbox offers hosted sandbox plans with explicit user, sandbox, and test-email caps, fitting teams that prefer a constrained sandbox model.

Postdrop is a web-based free tier centered on templates, exports, previews, and SendGrid integration, better for message design work than inbox automation.

testmail.app provides API and web access with a free 100-email monthly allowance, unlimited users and mailboxes, and one-day retention.

Verdict

Mailinator is a strong recommendation for engineering and QA teams that need private, repeatable incoming-message tests, scalable addresses, and API-driven automation. Its main reasons to look elsewhere are equally clear: it cannot send or submit forms, and public inboxes are inherently unsuitable for sensitive content.