MailPace vs Smtp.dev (2026): which should you pick?

Pick MailPace if

• Fits if you want your mail handled in the EU with no open tracking
• Works for Rails, Laravel or Node apps that want one flat plan

Look elsewhere if

• Skip it if you need a dedicated IP, as there is no such tier
• Watch out: received emails count toward the monthly volume along with sent ones
• Tight if you want a free plan, because 100 emails a month is given only on request
• Watch out: email content is kept for 30 days unless you ask for longer
• Not for you if you want open and click tracking, which it leaves out

Pick Smtp.dev if

• Fits if you test an app or test suite that sends email and want to read it back
• Works for CI pipelines that need a real inbox to check, with no real mail leaving

Look elsewhere if

• Skip it if you want to deliver real email: outbound only reaches accounts inside the sandbox
• Tight if you stay on Lite: 1 domain, 50 accounts and messages deleted after 7 days
• Tight if you need catch-all addresses, which start on Pro
• Watch out: messages are deleted at the end of the 7, 30 or 90 day window
• Watch out: the pricing page shows monthly prices only

MailPace

• There is one paid plan, so there is no tier with a dedicated IP address.
• Received emails count toward the monthly volume, as well as sent ones.
• The free plan of up to 100 emails a month is not advertised; the pricing page says to email the company.
• Email content is kept for 30 days, and a longer period has to be requested.

Smtp.dev

• It is a testing sandbox: on every plan, outbound mail is delivered only to accounts inside the sandbox, not to real inboxes.
• Lite keeps messages for 7 days and allows 1 domain and 50 accounts; catch-all accounts need Pro or Max.
• Messages are deleted automatically at the end of the plan's retention window of 7, 30 or 90 days.
• The pricing page shows monthly prices only and does not mention annual billing.

MailPace

HTTP API and SMTP server

Mail can be sent through a JSON HTTPS API or an SMTP server, with client libraries listed for Rails, Laravel, Node.js, Python, Go and more.

Inbound email

Incoming mail is received over SMTP and converted into HTTP webhooks that an application can process.

Idempotent requests

A request can carry an idempotency ID, so a retry does not send the same message twice.

No open or click tracking

MailPace says it never tracks email opens or clicks. It reports delivery acceptance rates instead.

Bounce and blocklist handling

Bounces are tracked automatically and bounced addresses are kept on a blocklist, with anti-spam checks on outgoing mail.

Smtp.dev

SMTP, IMAP and POP3 access

Standard mail clients and libraries connect with ordinary settings, with no SDK to install.

REST API

Accounts, messages, domains and tokens can be managed over the API, which is limited to 4096 requests a minute per user.

Message inspection

Shows headers, the MIME tree and the raw RFC 5322 source of each message, plus an HTML preview.

Own-domain receiving

Pointing a domain's or subdomain's MX record at the sandbox lets it receive mail from any service.

Deliverability audit

Checks sender configuration, HTML structure, links and content patterns that spam filters flag, grouped by severity.

CI use

Works with any CI system that can send over SMTP, with guides for GitHub Actions, Jenkins and GitLab CI.

MailPace

• Pay as you grow$10

  per month for the first 10,000 emails sent and received

  One plan with every feature included. The price follows monthly volume, set on a slider from 100 to 1,000,000 emails; extra emails are added to the bill.

Smtp.dev

• Lite$0

  1 domain, 50 accounts and 7 days of message retention; plus-sign aliasing but no catch-all.

• Pro$7

  per month

  5 domains, 25,000 accounts, 30 days of retention, and catch-all and aliasing.

• Max$20

  per month

  Unlimited domains and accounts, 90 days of retention, and catch-all and aliasing.