KumoMTA

The best MTA for
Enterprise Senders

Fast

KumoMTA is architected for the performance needed by enterprise senders, whether it's sending several million messages per hour through a single server, or scaling horizontally using Docker and Kubernetes.

Flexible

KumoMTA can replace straightforward configurations or be deeply integrated into your MailOps environment thanks to our Lua scripting engine and support for technologies including webhooks, AMQP, Kafka, Vault, Prometheus, Grafana, and direct database access.

Open-Source

KumoMTA is released under the Apache 2 OSI-approved license, with the ultimate transparency of having our sourcecode hosted on Github. Our community is actively involved and contributing to make KumoMTA better every day.

Making KumoMTA Possible For All

Our Sponsors

Our Growing Community

42000 +

Lines of Source Code

250 +

Pages of Documentation

460 +

Discord Members

250 +

Stars on GitHub

Join Our Community

Our Users

Our Memberships

BenDyer

Taguchi Marketing

Ben Dyer

"We’ve known Kumo’s founders and worked with them for many years, That personal connection was critical.

The fact they’re involved was enough to get us over the line to becoming a customer."

TomK

CEO

Tom Kuzler

"I really enjoy our MTA being open source and being able to see the issue and commit pipelines. It gives us a lot of transparency around where issues might sit that we never had before with a closed source MTA and lets us transparently know when bugs that are important to us are resolved. The pace of iteration and change that ultimately helps our end users is vastly improved."

Our Partners

ongage logo
Integration Partner

Ongage

Ongage is an email marketing platform that helps your business to personalize engagements and drive conversions through data.
postmastery
Services Partner

Postmastery

Postmastery is a leader in email deliverability and infrastructure management. They offer professional tools for email delivery and monitoring, enabling legitimate email senders to optimize their infrastructure and practices for email marketing and transactional email applications.
EmailConsul
Deliverability Partner

EmailConsul

EmailConsul is a comprehensive email analytics and monitoring solution designed to enhance email deliverability. The platform provides DMARC analytics, inbox placement, threat intelligence, blocklist monitoring, in-depth reporting, and more to help businesses maintain a healthy sender reputation and ensure messages reach their intended audience.
edgeneering-1
Services Partner

Edgeneering

Edgeneering LLC is a Web Development and technology company specializing in software & database development, high security data center hosting, and Open-Source consulting services.

Our Latest Blog Posts

KumoMTA metrics explained

One of the things that is incredibly important for any MailOps engineer is system observability. That is a big fancy...

Introducing the 2024 Fall Release

We're pleased to announce the Fall 2024 release, now available through our repos and Docker container.

Protect Your Shared Infrastructure With Tenant Throttles

One thing many ESPs have in common is the risk created by self-serve signups: a new user signs up for a free or even...

Choose the Best MTA

Find out more about how you can break free of the commercial license trap while leveraging the best MTA for enterprise senders.

Let's Talk

Chat with our founders and learn how easy it can be to move to KumoMTA.