Your emails work.
You just can't prove it.

Sendpit captures and inspects emails before they ever reach real users—so failures are caught early, not reported later.

An SMTP sandbox is a hosted service that captures outgoing emails during software development, preventing test emails from reaching real inboxes while providing inspection of HTML rendering, headers, and attachments.

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The email that never arrived

Your app
250 OK
SMTP accepted
?
Never arrived

Your app sent a password reset. SMTP returned 250 OK. Logs look clean.

Three days later, a support ticket: "I never got the email."

This happens constantly. Emails fail after they leave your server—silently, invisibly, without a trace. Spam filters. Typos. Provider throttling. Blacklists you didn't know you were on. The global average inbox placement rate is 83.5%, meaning one in six legitimate emails never reaches the inbox.Validity, 2025

And the worst part? You only find out when users complain. Or churn. Or tweet about it.

Validity, “2025 Email Deliverability Benchmark Report” (2025). Accessed Mar 18, 2026.
Your app
Sendpit Capture zone
Real users

A safe place to break your emails

Point your staging SMTP at Sendpit. Every email your app sends gets captured—not delivered.

Then inspect it. Check the HTML. Verify the headers. See if the "unsubscribe" link actually works. Test attachments. Preview mobile rendering.

Without an SMTP sandbox, test emails sent during development can reach real users, exposing internal data and damaging sender reputation.Mailtrap

All without a single email reaching a real inbox.

See how it works

Three steps. That's it.

01

Create a mailbox

Get SMTP credentials in ten seconds. One per environment, one per team—whatever you need.

02

Point your app at it

Swap your SMTP host. Standard port, TLS supported. Works with any language, any framework.

03

See every email

Open Sendpit. Every email your app sent is there. HTML rendered. Headers exposed. Attachments downloadable.

No code changes. No SDKs. No vendor lock-in.

Email failures cost more than you think

Onboarding drops

If your welcome email doesn't arrive, your user doesn't activate. That's not a bug. That's lost revenue.

Support load spikes

"I never got the reset link" is your most common ticket. Every one of those took five minutes. Multiply that by your user base.

Trust erodes quietly

Users don't always complain. They just stop opening. Or switch to a competitor. You never see the churn coming.

Most teams don't lose users because of bugs.
They lose them because something quietly didn't work.

Email testing tools compared

SendPit is a cloud-hosted SMTP sandbox. Here is how it compares to the most common alternatives for capturing test emails during development.

SendPit Mailtrap Mailpit MailHog
Type Cloud SaaS Cloud SaaS Self-hosted Self-hosted
Starting price Free / $5/mo Free / $14.99/mo Free (OSS) Free (OSS)
Setup time Under 1 minute Under 1 minute 5–15 minutes 5–15 minutes
Team sharing
No server required
Webhooks
Actively maintained No updates since 2020
Works in staging/CI Requires hosting Requires hosting

Pricing and features as of March 2026. Open-source tools are free to use but require your own infrastructure for team or CI/CD use.

Why email testing matters

21%

of emails never reach the inbox

Across all industries, roughly one in five legitimate emails is filtered, bounced, or lost before it reaches the recipient. For transactional emails like password resets and order confirmations, a single missed delivery directly impacts user experience.

75%

of email rendering issues are caught only after deployment

Most teams discover broken email templates, missing images, and malformed headers after the code has shipped. An SMTP sandbox catches these issues during development, before any email reaches a real user.

$0

infrastructure cost with a cloud sandbox

Self-hosted tools like MailHog and Mailpit require server provisioning, Docker configuration, and ongoing maintenance. A cloud-hosted sandbox like SendPit eliminates infrastructure overhead entirely. You get SMTP credentials and start testing.

2 min

average setup time with SendPit

Create a free account, copy your SMTP credentials, and update one environment variable. There are no SDKs to install, no Docker images to pull, and no servers to configure. SendPit works with any language or framework that supports SMTP.

What SendPit captures on every test email

Full HTML rendering with inline CSS
All SMTP headers (From, To, Reply-To, CC, BCC)
Raw email source (MIME structure)
Attachments with download and preview
Plain text fallback content
TLS encryption status

Built for teams that ship

Developers

Stop using your personal inbox for testing. Stop accidentally emailing production users from staging.

QA teams

Verify email flows without backend access. Screenshot the rendered email. Flag issues before they ship.

Product teams

Review transactional copy in context. Catch broken links, bad formatting, missing tokens—before launch.

Founders / Solo builders

You don't have a QA team. Sendpit is your QA team for email.

Not for everyone: Sendpit is for testing and development. If you're looking for a transactional email provider, marketing automation, or inbox deliverability tools—we're not that. And we don't pretend to be.

Let's be clear

Not an ESP. We don't send emails. We catch them.

Not a log viewer. We render and inspect—not just dump raw text.

Not error tracking. We don't monitor your app. We monitor your emails.

Not deliverability testing. We don't predict inbox placement—we help you make sure the email itself is correct.

Frequently asked questions

What is an SMTP sandbox?

An SMTP sandbox is a tool that captures outgoing emails from your application without delivering them to real recipients. It acts as a safe destination for test emails during development, so you can inspect subject lines, HTML rendering, headers, and attachments without risking accidental delivery to real people.

Do I need to change my application code to use Sendpit?

No. Sendpit uses standard SMTP, so you only need to update your SMTP host, port, username, and password in your application's environment configuration. Your application sends email the same way it always did—the only change is where those emails are delivered.

Is Sendpit free?

Yes. Sendpit has a permanent free tier that covers most small team needs. It is not a time-limited trial—you can use it as long as you want. Paid plans are available for teams that need more mailboxes, higher email volume, API access, or webhooks.

Can Sendpit send emails to real recipients?

No. Sendpit is exclusively an email testing tool. It captures emails for inspection but never delivers them to actual recipients. This is by design—the entire purpose is to prevent test emails from reaching real inboxes. For production email sending, you need a separate service like Postmark, Amazon SES, or Mailgun.

What programming languages and frameworks does Sendpit work with?

Sendpit works with any language or framework that can send email via SMTP. This includes Laravel, Rails, Django, Spring, Express, ASP.NET, and many more. If your application can connect to an SMTP server, it can use Sendpit.

You already test your code.
Why not your emails?

Every other system in your stack has visibility. Logs. Metrics. Alerts. Tests. Dashboards.

Email? You hit send and hope.
Sendpit fixes that. One SMTP change. Full visibility.

Get started free

No credit card. Free tier available. Setup in under two minutes.