--- title: KumoMTA - Enterprise Open-Source On-Prem/Private Cloud MTA description: KumoMTA is the open-source email infrastructure for enterprises and high-volume senders who want control and continuity without the risk, volatility, or pricing shocks that come with commercial providers. image: https://kumomta.com/hubfs/KUMO_Logo_NEW_Color.png --- [Skip to content](https://kumomta.com#main-content) [JUST RELEASED: The 2026 State of MailOps Report](https://kumomta.com/2026-state-of-mailops-report-download-page?hsLang=en) × [JUST RELEASED: The 2026 MTA Buyers Guide](https://kumomta.com/buyers-guide-2026-download?hsLang=en) × [![KUMO\_Logo\_NEW\_Color](https://kumomta.com/hs-fs/hubfs/KUMO_Logo_NEW_Color.png?width=118&height=32&name=KUMO_Logo_NEW_Color.png "KUMO_Logo_NEW_Color")](https://kumomta.com) - Technology - [Architecture](https://kumomta.com/technology/architecture) - [Features](https://kumomta.com/technology) - [Open Source](https://kumomta.com/technology/open-source) - [Support & Pricing](https://kumomta.com/pricing) - About Kumo - [About Us](https://kumomta.com/about) - [Events](https://kumomta.com/events) - [Customers](https://kumomta.com/customers) - [Contact Us](https://kumomta.com/contact) - Resources - [Documentation](https://docs.kumomta.com/) - [Migration Center](https://kumomta.com/migration-center) - [Migration Center Hub](https://kumomta.com/migration-center) - [Momentum](https://kumomta.com/momentum-migration-guide) - [PowerMTA](https://kumomta.com/replace-powermta-with-kumomtas-infrastructure-built-for-mailops) - [Halon](https://kumomta.com/halon-migration-guide) - [SendGrid](https://kumomta.com/sendgrid-alternative-migration) - [Hurricane MTA](https://kumomta.com/hurricanemta-alternative-socketlabs-migration) - [Blog](https://kumomta.com/blog) - [Community Forum](https://community.kumomta.com/) - Guides & Reports - [2026 MTA Buyers Guide](https://kumomta.com/buyers-guide-2026-download) - [2026 State of MailOps](https://kumomta.com/2026-state-of-mailops-report-download-page) - [YouTube Channel](https://www.youtube.com/channel/UC348UpfbnPgpKPAXIBW_JNQ) - [Github Repository](https://github.com/KumoCorp/kumomta) - [Contact Us](https://kumomta.com/contact?hsLang=en) - [Try It For Free](https://docs.kumomta.com/tutorial/quickstart/) # OPEN SOURCE EMAIL INFRASTRUCTURE for enterprises and high-volume senders [Get started for free](https://docs.kumomta.com/tutorial/quickstart/#) [Join our community](https://community.kumomta.com/?_gl=1*1e3dfd7*_gcl_au*MTQzNjQ3NTI2Ny4xNzcxNTM5MzY1*_ga*MzMxOTc4NjI2LjE3NTczNDY2NzM.*_ga_LNBCW1KF8J*czE3Nzc1MDIzNTMkbzIyJGcxJHQxNzc3NTAzNTYwJGoyJGwwJGgw) ### 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. [Read more](https://kumomta.com/technology?hsLang=en) ### 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. [Read more](https://kumomta.com/technology?hsLang=en) ### 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. [Read more](https://kumomta.com/technology?hsLang=en) [Let's Talk](https://kumomta.com/contact?hsLang=en) Architecture ### Revolutionized A leap ahead of re-architected commercial offerings [Read more ![chevron\_right (1)](https://kumomta.com/hubfs/chevron_right%20(1).svg) ](https://kumomta.com/technology/architecture?hsLang=en) Performance ### Redefined Send 10’s of millions of messages an hour on a single instance [Read more ![chevron\_right (1)](https://kumomta.com/hubfs/chevron_right%20(1).svg) ](https://kumomta.com/technology?hsLang=en) Confidence ### Restored No more black boxes when you own the code [Read more ![chevron\_right (1)](https://kumomta.com/hubfs/chevron_right%20(1).svg) ](https://kumomta.com/technology/open-source?hsLang=en) ![2026 Buyers Guide Cover Sm Background](https://kumomta.com/hs-fs/hubfs/2026%20Buyers%20Guide%20Cover%20Sm%20Background.png?width=3079&height=1195&name=2026%20Buyers%20Guide%20Cover%20Sm%20Background.png)   ### JUST RELEASED **The 2026 MTA Buyer’s Guide** Understand today's MTA landscape, evaluate trade-offs, and make infrastructure decisions with clarity and confidence [Download the guide](https://kumomta.com/buyers-guide-2026-download?hsLang=en) ## The world’s fastest-growing email community [![ActiveCampaign Logo\_Blue.bb](https://kumomta.com/hs-fs/hubfs/ActiveCampaign%20Logo_Blue.bb.png?width=176&height=18&name=ActiveCampaign%20Logo_Blue.bb.png)](https://www.activecampaign.com/) [![AWeber](https://kumomta.com/hubfs/AWeber.svg)](https://www.aweber.com/)[![Postmark](https://kumomta.com/hubfs/pm_logo.svg)](https://postmarkapp.com/) [![Aha Send](https://kumomta.com/hubfs/aha%20send%203.svg)](https://ahasend.com/) [![Maileroo](https://kumomta.com/hubfs/Maileroo_.svg)](https://maileroo.com/) #### The world's fastest-growing email community [![ActiveCampaign Logo\_Blue.sm3](https://kumomta.com/hs-fs/hubfs/ActiveCampaign%20Logo_Blue.sm3.png?width=350&height=36&name=ActiveCampaign%20Logo_Blue.sm3.png)](https://www.activecampaign.com/) [![Aha Send](https://kumomta.com/hs-fs/hubfs/logo-footer2x_-_350_wide-removebg-preview.png?width=350&height=62&name=logo-footer2x_-_350_wide-removebg-preview.png)](https://ahasend.com/) [![Postmark](https://kumomta.com/hubfs/pm_logo.svg)](https://postmarkapp.com/) [![AWeber](https://kumomta.com/hubfs/AWeber.svg)](https://www.aweber.com/) [![Maileroo\_](https://kumomta.com/hubfs/Maileroo_.svg)](https://maileroo.com/) [![Taguchi](https://kumomta.com/hs-fs/hubfs/Taguchi%20240x68.png?width=240&height=68&name=Taguchi%20240x68.png)](https://taguchi.com.au/) [![UnMTA logo sm1](https://kumomta.com/hs-fs/hubfs/UnMTA%20logo%20sm1.png?width=350&height=123&name=UnMTA%20logo%20sm1.png)](https://www.unmta.com/?ref=kumo) [![puresend 1](https://kumomta.com/hubfs/puresend%201.svg)](https://www.puresend.com/) [![Laposta](https://kumomta.com/hubfs/laposta_logo_sm.svg)](https://www.laposta.org/) [![Beehiiv](https://kumomta.com/hubfs/Beehiiv.svg)](https://www.beehiiv.com/) ## Invest in your business, not someone else’s business model ## The control and continuity you need without the risk, volatility, or pricing shocks that come with commercially-licensed providers ![check\_circle\_Long-term stability](https://kumomta.com/hubfs/check_circle_Long-term%20stability.svg) Long-term stability The confidence that your investment will remain secure and supported ![monetization\_on](https://kumomta.com/hubfs/monetization_on.svg) Cost predictability and fairness No surprise price hikes or exploitative renewals ![beenhere](https://kumomta.com/hubfs/beenhere.svg) Control and resilience Guaranteed access to the technology and authority over your deployment ![stars](https://kumomta.com/hubfs/stars.svg) A trusted partnership A relationship built on stewardship and transparency ![zoom\_out\_map](https://kumomta.com/hubfs/zoom_out_map.svg) Performance, scalability, and control Deliver millions of emails an hour without risk of data loss ## [Read more about how KumoMTA delivers lasting value![chevron\_right (1)](https://kumomta.com/hubfs/chevron_right%20(1).svg)](https://kumomta.com/technology/open-source?hsLang=en)   “With features like traffic shaping, automation and management for IP pools, and all the web hooks that they provide, Kumo allows us to write a lot of automation around it. Kumo is now part of AhaSend where I spend the least amount of time: it's just doing what it's supposed to do without any problems. Nice!” **Farhad Hedayatirfad** AhaSend ❮ ❯ “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.” **Ben Dyer** Taguchi Marketing ❮ ❯ “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.” **Tom Kulzer** AWeber ❮ ❯ “Kumo appears to be capable of far higher single-node throughput than our legacy MTA platform, which has far-reaching implications for increasing our capacity to handle larger campaigns in tighter timeframes. We expect to see significant improvements when warming up new IPs and onboarding new customers also.” **Ben Dyer** Taguchi Marketing ❮ ❯ ## Our **Community** 90000 Lines of Source Code 650 + Pages of Documentation 700 + Discord Members 350 + Stars on GitHub ## THE KUMO COMMUNITY by the numbers Making KumoMTA better every day Expedited innovation and vulnerability identification is performed by a global community of independent developers, security researchers, and enterprises who are continually auditing code and identifying improvements. [Join the Kumo Community today](https://community.kumomta.com/?_gl=1*1e3dfd7*_gcl_au*MTQzNjQ3NTI2Ny4xNzcxNTM5MzY1*_ga*MzMxOTc4NjI2LjE3NTczNDY2NzM.*_ga_LNBCW1KF8J*czE3Nzc1MDIzNTMkbzIyJGcxJHQxNzc3NTAzNTYwJGoyJGwwJGgw) ![](https://kumomta.com/hubfs/code.svg) **110,000** Lines of code ![](https://kumomta.com/hubfs/pages.svg) 1,000+ Pages of documentation ![](https://kumomta.com/hubfs/discord.svg) 850+ Community members ![](https://kumomta.com/hubfs/githnub.svg) 500+ Stars on GitHub Latest news and info ## Our **Memberships** [![M3AAWG](https://kumomta.com/hs-fs/hubfs/M3AAWG-vert-highrez-300-res%5B2%5D.png?width=320&height=130&name=M3AAWG-vert-highrez-300-res%5B2%5D.png)](https://www.m3aawg.org/) ![BenDyer](https://kumomta.com/hs-fs/hubfs/BenDyer.jpg?width=200&height=200&name=BenDyer.jpg) 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](https://kumomta.com/hs-fs/hubfs/TomK.jpg?width=200&height=200&name=TomK.jpg) 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](https://kumomta.com/hs-fs/hubfs/logoJpg@4x-100-2.jpg?width=804&height=234&name=logoJpg@4x-100-2.jpg) Integration Partner ### Ongage Ongage is an email marketing platform that helps your business to personalize engagements and drive conversions through data. [Learn More](https://www.ongage.com/) ![postmastery](https://kumomta.com/hs-fs/hubfs/Imported%20sitepage%20images/postmastery.webp?width=350&height=81&name=postmastery.webp) Services Partner ### Postmastery Postmastery is a leader in email deliverability and email infrastructure management. They are an authorized EU-based support provider of Kumo for the purpose of selling and providing Support Services to KumoMTA End Users. [Learn More](https://www.postmastery.com/kumomta/) ![EmailConsul](https://kumomta.com/hs-fs/hubfs/logo.png?width=463&height=72&name=logo.png) 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. [Learn More](https://emailconsul.com) [![](https://kumomta.com/hubfs/baobun-vault_1.91x1_1200x628.png)](https://kumomta.com/blog/integrating-openbao?hsLang=en) [DKIM](https://kumomta.com/blog/tag/dkim?hsLang=en), [SMTP](https://kumomta.com/blog/tag/smtp?hsLang=en), [KumoMTA Integrations](https://kumomta.com/blog/tag/kumomta-integrations?hsLang=en), [OpenBao](https://kumomta.com/blog/tag/openbao?hsLang=en) - [Tom Mairs](https://kumomta.com/blog/author/tom-mairs?hsLang=en) - September 10, 2026 ### [Integrating OpenBao with KumoMTA](https://kumomta.com/blog/integrating-openbao?hsLang=en) This is effectively a guest post from CM.com, which uses KumoMTA as its email infrastructure. Their Engineering team... [Read more](https://kumomta.com/blog/integrating-openbao?hsLang=en) [![Cartoon strip of email team discussing methods.](https://kumomta.com/hubfs/AI-Generated%20Media/Images/Cartoon%20Strip%20with%20Team%20Discussing%20Email%20Strategies.png)](https://kumomta.com/blog/the-case-for-tuneable-architecture?hsLang=en) [Tuneable Architecture](https://kumomta.com/blog/tag/tuneable-architecture?hsLang=en), [Email Infrastructure](https://kumomta.com/blog/tag/email-infrastructure?hsLang=en), [In-house vs Outsourced](https://kumomta.com/blog/tag/in-house-vs-outsourced?hsLang=en) - [Tom Mairs](https://kumomta.com/blog/author/tom-mairs?hsLang=en) - August 24, 2026 ### [The case for tuneable architecture](https://kumomta.com/blog/the-case-for-tuneable-architecture?hsLang=en) A month from now, I will be in Toronto discussing the benefits of having tunable control over your email sending. Join... [Read more](https://kumomta.com/blog/the-case-for-tuneable-architecture?hsLang=en) [![IT Sovereignty Explaned](https://kumomta.com/hubfs/IT%20Sovereignty.png)](https://kumomta.com/blog/europes-burgeoning-sovereign-it-movement-explained?hsLang=en) [mailops](https://kumomta.com/blog/tag/mailops?hsLang=en), [infrastructure](https://kumomta.com/blog/tag/infrastructure?hsLang=en), [data sovereignty](https://kumomta.com/blog/tag/data-sovereignty?hsLang=en), [Europe](https://kumomta.com/blog/tag/europe?hsLang=en), [EU](https://kumomta.com/blog/tag/eu?hsLang=en) - [Mike Hillyer](https://kumomta.com/blog/author/mike-hillyer?hsLang=en) - July 30, 2026 ### [Europe's burgeoning sovereign IT movement explained](https://kumomta.com/blog/europes-burgeoning-sovereign-it-movement-explained?hsLang=en) We recently published a case study documenting the founding story of Lettermint, most likely one of the first ESPs in... [Read more](https://kumomta.com/blog/europes-burgeoning-sovereign-it-movement-explained?hsLang=en) Ready to take a test spin? [Start sending](https://docs.kumomta.com/tutorial/quickstart/) ## 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. [CONTACT US](https://kumomta.com/contact?hsLang=en) [![KUMO\_Logo\_Files\_Color 1](https://kumomta.com/hubfs/KUMO_Logo_Files_Color%201.svg "KUMO_Logo_Files_Color 1")](https://kumomta.com?hsLang=en) ##### Proud member of ![maawg 1](https://kumomta.com/hs-fs/hubfs/maawg%201.png?width=226&height=24&name=maawg%201.png "maawg 1") [Follow us on LinkedIn](https://www.linkedin.com/company/91414337/) [Follow us on Github](https://github.com/KumoCorp/kumomta) [Follow us on Discord](https://discord.com/servers/kumomta-1072980126737907824) [Follow us on Facebook](https://www.youtube.com/channel/UC348UpfbnPgpKPAXIBW_JNQ) #### Explore KumoMTA - [Open Source](https://kumomta.com/technology/open-source) - [Features](https://kumomta.com/technology) - [Pricing](https://kumomta.com/pricing) - [Case Studies](https://kumomta.com/customers) - [About Us](https://kumomta.com/about) - [Privacy](https://kumomta.com/privacy) #### Resources - [Blog](https://kumomta.com/blog) - [Documentation](https://docs.kumomta.com) - [Community Forum](https://community.kumomta.com/) - [FAQ](https://docs.kumomta.com/faq/) - [YouTube Channel](https://www.youtube.com/channel/UC348UpfbnPgpKPAXIBW_JNQ) - [GitHub Repository](https://github.com/KumoCorp/kumomta) Get periodic updates about the latest releases, features, and news around KumoMTA. - [© 2026 Kumo Corp, All rights reserved. KumoMTA and the Kumo logo are registered trademarks of Kumo Corp. ](https://kumomta.com/privacy)