CHOOSE SMTPBOX WHEN
A hosted team sandbox is the priority.
Teams whose main requirement is shared SMTP capture and API assertions with predictable sandbox pricing.
View SMTPBox pricing →API EMAIL TESTING
SMTPBox vs MailSlurp
SMTPBox vs MailSlurp for email testing workflows.
SMTPBox focuses on capturing and inspecting development email. MailSlurp covers a broader set of email workflows and testing tools.
SIDE BY SIDE
Choose the setup that fits.
| Area | SMTPBox | MailSlurp |
|---|---|---|
| Permanent free plan | Yes, no card required | Yes, no card required |
| External recipient delivery | Never forwards sandbox mail | Paid plans support external delivery |
| Product focus | SMTP capture and API inspection | Email workflows and testing tools |
| Paid plan structure | One £14.99 monthly plan | Pro, Team and Enterprise |
| Hosted service | Yes | Yes |
Reviewed 7 September 2026 against MailSlurp plan details. Features and limits can change; follow the source for current terms.
CHOOSE MAILSLURP WHEN
The alternative better matches your workflow.
MailSlurp may suit workflows requiring its rendering, inbox placement or paid external delivery capabilities.
Move a test workflow from MailSlurp
Separate SMTP capture tests from tests that depend on MailSlurp external delivery or other specialised features. Move capture workflows to an SMTPBox inbox, then adapt API assertions to SMTPBox message UIDs, response envelopes and wait filters. SMTPBox cannot replace production email delivery.
- Create the destination project and inbox in SMTPBox.
- Generate an inbox SMTP credential and update non-production settings.
- Use STARTTLS on 587 or 2525, or implicit TLS on 465.
- Send a synthetic test email and confirm it appears in the expected inbox.
- Adapt automated tests before removing the old test integration.
Use the SMTP setup guide, API reference and framework guides.
TRY SMTPBOX FREE
Catch test emails, not customers.
Start with 2,500 sandbox emails each month and no credit card.
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