---
title: "Mailosaur Alternative for Email Testing"
description: "Mailosaur and smtp.dev side by side for email tests: plans, quotas, custom domains, and IMAP. When SMS keeps you on Mailosaur, and how to port your tests."
canonical_url: "https://smtp.dev/docs/alternatives/mailosaur/"
---

> Index of every page on this site: [llms.txt](https://smtp.dev/llms.txt)

Mailosaur is built for QA automation across email and SMS. A test waits for a message, pulls out a link or a code, and carries on. smtp.dev covers the email half of that, including one-time codes sent by email. If your suite also reads codes from SMS or an authenticator app, stay on Mailosaur.

For email-only suites, the address model is the difference to understand first. A Mailosaur inbox has its own domain, like `abc123.mailosaur.net`, and any address on it works without setup. Here, addresses live on your own domain. Each one is an account you create, or a plus alias of one, like `qa+anything@test.example.com`, on any plan. A [catch-all](https://smtp.dev/docs/guides/catch-all/) on Pro or Max accepts every address.

## At a Glance

<table>
<thead>
  <tr>
    <th>
      
    </th>
    
    <th>
      Mailosaur
    </th>
    
    <th>
      smtp.dev
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Price per month
    </td>
    
    <td>
      Personal from $20, Core from $50, billed yearly. Enterprise is quoted
    </td>
    
    <td>
      $0, $7, or $20
    </td>
  </tr>
  
  <tr>
    <td>
      Free
    </td>
    
    <td>
      A 14-day trial
    </td>
    
    <td>
      Lite, with no time limit
    </td>
  </tr>
  
  <tr>
    <td>
      Inbound email
    </td>
    
    <td>
      15,000 a month and 500 a day on Personal. 75,000 and 2,500 on Core
    </td>
    
    <td>
      No message quota
    </td>
  </tr>
  
  <tr>
    <td>
      Addresses
    </td>
    
    <td>
      Any address on the inbox's <code>
        mailosaur.net
      </code>
      
       domain
    </td>
    
    <td>
      Accounts on your domain and their plus aliases. Any address with a catch-all on Pro and Max
    </td>
  </tr>
  
  <tr>
    <td>
      Your own domain
    </td>
    
    <td>
      Enterprise
    </td>
    
    <td>
      Every plan
    </td>
  </tr>
  
  <tr>
    <td>
      Reading mail
    </td>
    
    <td>
      API and client libraries on every plan. IMAP and POP3 on Core and Enterprise
    </td>
    
    <td>
      REST API, SSE, IMAP, and POP3 on every plan
    </td>
  </tr>
  
  <tr>
    <td>
      SMS and authenticator codes
    </td>
    
    <td>
      Core add-on, from $37.50 a month
    </td>
    
    <td>
      No. Codes sent by email work like any other message
    </td>
  </tr>
  
  <tr>
    <td>
      Client previews
    </td>
    
    <td>
      Core add-on, from $25 a month
    </td>
    
    <td>
      No. Open the account in a mail client over IMAP
    </td>
  </tr>
  
  <tr>
    <td>
      Users
    </td>
    
    <td>
      1 on Personal, up to 3. 5 seats on Core. SSO and SCIM on Enterprise
    </td>
    
    <td>
      Single user
    </td>
  </tr>
</tbody>
</table>

## Stay on Mailosaur When

- **A test reads codes from SMS or an authenticator app.** smtp.dev only receives email.
- **You need client previews or accessibility checks.** Both are on Core. The [audit](https://smtp.dev/docs/features/message/#audit) here checks sender configuration, HTML structure, links, and images, but doesn't render the message in other clients.
- **Any local part should work with no setup, on the cheapest plan.** That's how a Mailosaur inbox behaves. Lite covers `qa+anything@` with plus aliases, but arbitrary addresses take a catch-all, which starts on Pro.
- **Several people need logins, SSO, or SCIM.**
- **Your tests use Mailosaur's client libraries and pass.** There's nothing to gain from rewriting them.

## Reasons to Switch

- **Your own domain without Enterprise.** Mailosaur's documentation lists receiving on a custom domain as Enterprise only. Every plan here takes a domain, and a [subdomain works](https://smtp.dev/docs/setup/domain/) while the apex keeps its production MX.
- **Signup forms that block disposable domains.** `mailosaur.net` is on the open-source disposable-email-domains blocklist. If your app checks addresses against it, a test address can be rejected before any email goes out. Your own domain isn't on the list.
- **IMAP and POP3 on the cheapest plan.** Personal doesn't include them. Every account here is an [IMAP and POP3 mailbox](https://smtp.dev/docs/setup/account/), Lite included.
- **Large runs.** Personal accepts 500 emails a day, so a nightly suite that sends 600 runs out partway through. Plans here don't count messages.
- **A free plan that stays free.** Lite is $0 with no trial clock: 1 domain, 50 accounts, messages kept 7 days.

## Porting a Test

If the app already sends through your provider, change the test recipient from `user@abc123.mailosaur.net` to an address on your test domain. The MX record routes it here.

If the app submits mail to Mailosaur over SMTP, point it at `send.smtp.dev`, port 587 with STARTTLS, and log in with the sending account's address and password. `send.smtp.dev` delivers only to accounts in your sandbox, so every recipient has to be an account you created or a plus alias of one, or any address on your domain once you have a catch-all.

The Mailosaur inbox ID in your tests becomes two IDs here: the account, and its mailbox whose `path` is `INBOX`. Waiting for a message becomes a poll of that mailbox, newest first:

```bash
curl "https://api.smtp.dev/accounts/{accountId}/mailboxes/{mailboxId}/messages" \
  -H "X-API-KEY: $SMTP_DEV_API_KEY"
```

Mailosaur's libraries wrap that wait for you. Here it's a few lines: `findMessage` with `expect.poll` in the [Playwright guide](https://smtp.dev/docs/guides/e2e/), the `waitForEmail` task in the [Cypress guide](https://smtp.dev/docs/guides/cypress/), or [SSE](https://smtp.dev/docs/api/#real-time-updates) if you'd rather not poll.

<note>

Mailosaur's plans, limits, and add-on prices are from its pricing page. Custom domains and IMAP availability are from its documentation. The blocklist is disposable-email-domains on GitHub. All checked November 9, 2026.

</note>

## Sitemap

See the full [sitemap](https://smtp.dev/sitemap.md) for all pages.