---
title: "KumoMTA"
pageType: "tool-profile"
schemaVersion: "1.0"
snapshotId: "tv-20260911-8ab5e3f1311b"
generatedAt: "2026-09-11T07:01:56.000Z"
canonicalUrl: "https://toolvitals.com/tools/kumomta/"
jsonUrl: "https://toolvitals.com/api/agent/tools/kumomta"
indexable: true
---

# KumoMTA

The first Open-Source  high-performance MTA developed from the ground-up for high-volume email sending environments.

## Decision context

- Status: active
- ToolVitals score: 89/100
- Health score: 91/100
- Shipping score: 86/100
- Score mode: verdict
- Data confidence: 90/100
- Source coverage: 90/100
- Last evidence check: 2026-09-11

## Classification

- Use case: Self-Hosted Email Server (self-hosted-email-server)
- Category: Communication (communication)
- Tool mode: Source-visible project
- Openness: OSI-approved OSS
- License: Apache-2.0
- Tags: open-source, email, email-server, email-template, mta, mta-server, smtp, smtp-mail, smtp-mailer, smtp-relay, smtp-server, smtpd, mail-server, email-infrastructure, high-volume-email, self-hosted

## Public repository signals

- Repository: [KumoCorp/kumomta](https://github.com/KumoCorp/kumomta)
- Stars: 530 (adoption context only)
- Forks: 102
- Open issues: 91
- Last commit date: 2026-09-11
- Releases in 90 days: 1

## Source receipts

- [Official website](https://kumomta.com/) — checked 2026-09-11
- [Source repository](https://github.com/KumoCorp/kumomta) — checked 2026-09-11

## Discovery status

- Search indexable: yes
- Reason: sufficient tool evidence

## Interpretation limits

- ToolVitals scores summarize bounded public maintenance, shipping, openness, and evidence signals. They are not user-review ratings.
- GitHub stars and related popularity metrics are adoption context, not quality evidence.
- Missing values mean not collected or not confidently established; they do not mean zero.
- Public signals do not prove security, uptime, support quality, customer satisfaction, or production suitability.
- Verify material decisions against the linked first-party sources and your own requirements.