What is Mailpit?
A minimal email testing tool that intercepts SMTP traffic and provides a web UI plus REST API for validating and testing email functionality during development.
Platform & deployment
Independently observed- Web
- Self-hosted
Integrations (1)
Independently observed- SpamAssassin
Security & compliance
Known vulnerabilities: 13 (13 in the last 12 months), max severity HIGH sourcea count reflects scale & disclosure, not quality
Mailpit alternatives
Other email testing dev we track, ranked by the same independent score.
- Testmail.appProgrammable email testing service for developers and QA automating end-to-end test verificationlow · 42%
- Maildevlow · 24%
- MailosaurPlatform for testing email and SMS communications end-to-end before productionmedium · 55%
- Email on AcidEmail testing and validation platform for pre-send campaign quality assurancemedium · 66%
- GreenMaillow · 31%
- MailSlurpOn-demand email and SMS testing platform for developersmedium · 54%
The Vioscale score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Mailpit, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Release cadence | 94 | 0.05 | 4.9 | ✓ |
| Development activity | 49 | 0.09 | 4.6 | ✓ |
| Stars | 76 | 0.03 | 2.0 | ✓ |
| Integrations | 9 | 0.07 | 0.6 | ✓ |
| Capabilities | 0 | 0.08 | 0.0 | - |
| Dependent projects | 0 | 0.06 | 0.0 | ✓ |
| Security posture | 0 | 0.07 | 0.0 | - |
| Package downloads | 0 | 0.14 | 0.0 | - |
| Security score | 0 | 0.04 | 0.0 | - |
| Developer Q&A activity | 0 | 0.06 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 36 | mediumsource · 2026-08-26 · 65% |
Adoption
Integrations
| Attribute | Value | Evidence |
|---|---|---|
| Count | 1 | mediumsource · 2026-08-20 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | Go | highsource · 2026-08-26 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | MIT | highsource · 2026-08-26 · 95% |
Release
Security
| Attribute | Value | Evidence |
|---|---|---|
| Vulnerabilities | Count: 13 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=go&package_name=github.com%2Faxllent%2Fmailpit&per_page=100 · Last 12m: 13 · Max severity: HIGH | highsource · 2026-08-26 · 90% |