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A Mailtrap alternative for testing emails before they ship

Emailens checks your email before your client opens it: a free account catches test mail at a private @try address with live previews across 21 inboxes (five without an account). Dev adds sandbox SMTP. It does not send production email.

The checker needs a computer screen.

Mailtrap is the better tool if

  • You want your test sandbox and your production sending with one provider. Emailens does not send production email.

Emailens is the better tool if

  • You want test mail caught and checked in a live preview of every client in one place (a private @try address, Free; sandbox SMTP, Dev).
  • Your tests wait for an email and read the code or link in it (sandbox API, Dev).
  • You want a pull request to fail when an email breaks in Outlook (GitHub Action, Pro).
  • You want real-client screenshots of an email when they matter (real-device checks, Dev + Real).

Do you keep real screenshots? Yes, metered.

A real-device check screenshots your email in real Outlook on Windows and Mac, Apple Mail on Mac and iPad, Gmail and Yahoo on the web and Android, and Proton: 20 checks a month on Dev + Real, 50 on Pro + Real. Here is the Emailens probe for one feature on real installs, beside our live preview.

border-radius:

Works in 16 of 21 · partial in 4 · not supported in 1

Three clients, picked by one rule: the one where border-radius is not supported, one where it is partial, one where it works. Where it is supported you should see rounded corners.

Outlook Classic

caniemail: border-radius is not supported in Outlook Classic.

Emailens live preview of Outlook Classic Our live preview The same probe in the Emailens live preview of Outlook Classic
Yahoo Mail

caniemail: border-radius is partly supported in Yahoo Mail.

Emailens live preview of Yahoo Mail Our live preview The same probe in the Emailens live preview of Yahoo Mail

Partial support. Shorthand for setting elliptical borders with the slash / notation is not supported e.g. border-radius: 27% 73% 70% 30% / 30% 34% 66% 70%;.

Outlook 365

caniemail: border-radius works in Outlook 365.

Emailens live preview of Outlook 365 Our live preview The same probe in the Emailens live preview of Outlook 365

This Outlook.com install drops the <style> in the head, so only inline styles apply.

Also captured, not counted as evidence (3)

Every account includes one free real-device check in classic Outlook, Outlook for Mac and Apple Mail, after you verify your email and run one preview, while this month's free capacity lasts. How real-device checks work →

border-radius in every client →

The fix for Outlook Classic

Use VML to render rounded buttons in Outlook

after 
<!--[if mso]>
<v:roundrect xmlns:v="urn:schemas-microsoft-com:vml"
  href="https://example.com"
  style="height:44px; v-text-anchor:middle; width:200px;"
  arcsize="14%" strokecolor="#6d28d9" fillcolor="#6d28d9">
  <w:anchorlock/>
  <center style="color:#fff; font-family:Arial,sans-serif;
    font-size:14px; font-weight:bold;">Click Here</center>
</v:roundrect>
<![endif]-->
<!--[if !mso]><! -->
<a href="https://example.com"
  style="background-color: #6d28d9; color: #fff;
         padding: 12px 32px; border-radius: 6px;
         text-decoration: none; display: inline-block;">
  Click Here
</a>
<!-- <![endif]-->
Show the original
before 
<a href="https://example.com"
  style="background-color: #6d28d9; color: #fff;
         padding: 12px 32px; border-radius: 6px;
         text-decoration: none; display: inline-block;">
  Click Here
</a>

The checker needs a computer screen.

A free account opens all 21 clients and keeps your checks for 7 days. Create a free account →

What it costs

  • Mailtrap Free · 50 test emails $0
  • Mailtrap Basic · $14 a month billed yearly; 500 test emails $17 a month
  • Mailtrap Team · $34 a month billed yearly; 5,000 test emails $42 a month
  • Mailtrap Business · $99 a month billed yearly; 50,000 test emails $123 a month
  • Mailtrap Enterprise · $399 a month billed yearly; unlimited test emails $498 a month

Read at Their pricing page on 11 Nov 2026

Emailens, by what you need

A free account: 30 checks a day in all 21 clients, kept for 7 days.

Sandbox SMTP and the API

Sandbox SMTP (Dev). Dev is $9 a month. Share links for your client's sign-off, a test inbox and an API key. See the plans →

Real-client screenshots

Dev + Real is $19 a month, with 20 real-device checks a month. Real-device plans →

The pull-request gate in CI

GitHub Action (Pro). Pro is $19 a month. The pre-send gate in CI, and the history behind every check. See the plans →

Both

Pro + Real is $39 a month, with 50 real-device checks a month.

Dev + Real and Pro cost the same: one adds real-client screenshots, the other the pull-request gate in CI.

Row by row

Test inbox
A private @try address (Free); sandbox SMTP and API (Dev)
Mailtrap: Its Email Sandbox captures SMTP traffic from staging and development.checked 11 Nov 2026
Rendering check
Every email in a live preview of all 21 clients (Free; five without an account)
Mailtrap: Device Previews, a paid add-on, shows the email across clients and devices.checked 11 Nov 2026
Which CSS fails where, and the fix
Per-client findings with the engine's fix (Free)
Mailtrap: An HTML Checker reports HTML and CSS support across clients and how to fix errors.checked 11 Nov 2026
Pull-request gate
GitHub Action (Pro)
Mailtrap: A sandbox API for automated testing.checked 11 Nov 2026
Real-client screenshots
Real Outlook on Windows and Mac, Apple Mail on Mac and iPad, Gmail and Yahoo on the web and Android, and Proton: 20 checks a month (Dev + Real), 50 (Pro + Real); one free check in classic Outlook, Outlook for Mac and Apple Mail with an account
Mailtrap: Device Previews returns screenshots of the mobile, desktop and web client configurations you pick.checked 12 Nov 2026
AI coding assistants
MCP server (Free)
Mailtrap: An MCP server for AI agents, covering sending, inbound mail and the sandbox.checked 11 Nov 2026
Production sending
Not offered
Mailtrap: Sends production email through an email API and SMTP.checked 11 Nov 2026

Moving over from Mailtrap

  1. Create a free account and send a test email to your private @try address.
  2. Point your app's SMTP settings at the sandbox (Dev).
  3. Wait for the email in your tests and read its code or link through the API (Dev).

Questions

What do I lose moving from Mailtrap?
Production sending. Emailens catches and checks test mail; it does not deliver email to your customers, so you keep a sending provider.
Can I try Emailens without paying?
Yes. The checker needs no signup: five clients, 3 checks a day, results kept for an hour. A free account opens all 21 clients and keeps your checks for 7 days. It allows 30 checks a day. Every account includes one free real-device check in classic Outlook, Outlook for Mac and Apple Mail, after you verify your email and run one preview, while this month's free capacity lasts.
Which plan does the GitHub Action need?
Pro. The Action's pre-send gate is a Pro feature: on Free and Dev it answers "The pre-send gate is available on the Pro plan."

Sources

Real captures 14 Oct 2026 on 10 installs · caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 9 Mar 2021 · data last changed 10 Nov 2026

Check an email you sent with Mailtrap

The checker needs a computer screen.

A free account opens all 21 clients and keeps your checks for 7 days. Create a free account →

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