MailCatcher vs SMTP Labs
MailCatcher
mailcatcher.meSMTP Labs
smtp.devSide by side
| Figure | MailCatcher | SMTP Labs |
|---|---|---|
| Price from | — | $7/mo |
| Free plan | — | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| macOS | Yes | — |
| Linux | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 0 | 3 |
| Spec score · Email Testing Software | 7.2 (#22) | 8.4 (#8) |
| Integrations | The site gives setup instructions for Rails, PHP, and Django applications. | The maker documents CI use with GitHub Actions, Jenkins, GitLab CI, and CircleCI, using standard SMTP and the REST API. |
| Purpose | MailCatcher runs an SMTP server that catches messages and displays them in a web interface. | SMTP Labs is an email testing service that receives test email over SMTP and lets users inspect it through the web UI, IMAP, POP3, or API. |
| Support | The maker asks users to file an issue and include the complete message when reporting processing problems. | The terms state the company has no support or maintenance obligation except as may be included in a paid subscription plan. |
Plans
In their own words
MailCatcher
MailCatcher has no write-up on Specifiction yet; its figures are above.
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.