MailSlurp vs SMTP Labs
MailSlurp
mailslurp.comSMTP Labs
smtp.devSide by side
| Figure | MailSlurp | SMTP Labs |
|---|---|---|
| Price from | $19.99/mo | $7/mo |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | Yes | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Plans published | 9 | 3 |
| Spec score · Email Testing Software | 8.9 (#5) | 8.4 (#8) |
| Integrations | The integrations directory lists 79 items, including SDKs, Playwright, Cypress, Selenium, BrowserStack, Zapier, Power Automate, UiPath, Postman, GraphQL and webhooks. | The maker documents CI use with GitHub Actions, Jenkins, GitLab CI, and CircleCI, using standard SMTP and the REST API. |
| Licence | The hosted MailSlurp service is proprietary, while public official SDK repositories such as the TypeScript client are MIT licensed. | The terms grant a limited, revocable, non-transferable license for personal or internal business use and prohibit copying, reverse engineering, hosting, or commercial exploitation. |
| Security controls | The security policy states TLS in transit, AES-256 encryption at rest, AWS RDS/S3 storage, daily backups, VPNs, network ACLs, penetration testing and RBAC. | The privacy policy says the service uses encryption, firewalls, SSL technology, and third-party authentication protections. |
| Support | The support page offers guides and direct contact for account, billing, delivery, and technical issues. | The terms state the company has no support or maintenance obligation except as may be included in a paid subscription plan. |
| What it does | MailSlurp provides programmable email addresses, phone numbers, messaging APIs and testing workflows for developers and QA teams. | SMTP Labs is a hosted email-testing sandbox where inbound messages can be inspected through a web interface, IMAP, POP3, or REST API. |
Plans
MailSlurp
- FreeFree
- FreeFree
- Starter$19.99 a month
- Starter$19.99 a month
- Pro$49.99 a month
- Pro$49.99 a month
- Growth$129.99 a month
- Growth$129.99 a month
- EnterprisePriced on request
In their own words
MailSlurp
MailSlurp provides tools to build, test, and automate email and SMS workflows. Users can create temporary or permanent inboxes and handle messages through APIs, SDKs, SMTP, IMAP, and webhooks. It supports end-to-end tests for scenarios including OTP, MFA, magic links, and load testing, as well as device previews, email audits, and inbox placement checks. Pipelines can route messages and attachments using webhooks, forwarding, and automatic replies. AI extraction can turn emails and attachments such as PDFs and images into structured JSON using prompts, schemas, and OCR. Listed integrations include Playwright, Cypress, Selenium, HubSpot, Braze, Mailchimp, Zapier, and AI assistants through MCP. A REST API and official SDKs cover several programming languages. The free plan has capped allowances, including 500 received emails and 1,000 sandbox sends per month. Starter costs $19.99/mo; custom domains and phone numbers require Pro on Free and Starter plans. MailSlurp is web- and API-accessible.
SMTP Labs
SMTP Labs is an email testing service that receives test messages over SMTP and lets you inspect them on the web, through IMAP or POP3, or via an API. Messages remain in a sandbox and cannot reach external recipients. Inspection includes HTML and plain text, headers, MIME structure, raw source, and attachments. SPF, DKIM, and DMARC checks appear in the interface and API, while a deliverability audit reviews sender configuration, HTML, links, and content patterns associated with spam filters. The REST API covers domains, accounts, mailboxes, messages, and tokens; server-sent events can push new messages. SMTP, IMAP, and POP3 work without a vendor SDK. The Lite plan is free at free with one domain, 50 accounts, and seven-day retention. Pro costs $7 a month, and Max costs $20 a month, with longer retention and expanded domains or accounts. Email and account data are primarily processed in the United States.