Postfix
iRedMail
Zimbra
Exim
mailcow
Roundcube
Sendmail
Mail-in-a-box
KumoMTA
PowerMTA
MailerQ
Halon MTA
GreenArrow Engine
Exim
NikaMail
SendGrid Email API
KumoMTA is an open source Message Transfer Agent (MTA) designed to provide high performance outbound email functionality.
The KumoMTA project was founded by a group of email industry veterans with decades of experience building and managing high-performance On-Prem MTAs and is supported by a community of some of the largest senders in the world. While paying attention to the lessons of history, KumoMTA was designed from the ground up with new tech as opposed to modifying something that already existed. We specifically avoided making a modification of Postfix or Exim or some other existing MTA and instead wrote entirely new code in Rust.
So how did we come up with the name KumoMTA? We set out to build a cloud deployable on-premises MTA that was flexible enough to install both on bare metal and in a public or private cloud. Kumo means cloud in Japanese, so "KumoMTA" is a Cloud MTA.
High volume commercial MTAs tend to have closed source code and steep license fees. Neither of these are particularly bad as long as the software is maintained and is flexible enough to modify. However, the kind of people who typically install very complex high-volume MTAs usually want to modify it or integrate it into other systems. Providing an open source option allows people to modify the code as needed, and contribute modifications easily to the community. The email community is full of very smart, creative people who now have an avenue to contribute to a wider community project.
Postfix KumoMTANo features have been listed yet.
KumoMTA's answer:
KumoMTA is the only high-performance, highly flexible MTA built for senders that is Open-Source with a free license.
KumoMTA's answer:
KumoMTA was built by a team of industry veterans to address a need in the market for an Open-Source solution that has the performance and flexibility of the commercial MTA offerings but without the restrictive licensing that the industry has grown weary of.
KumoMTA's answer:
KumoMTA is built on Rust, with Lua used for its Config as Code engine, making extensive customization and integrations straightforward while providing extreme performance and safety.
KumoMTA's answer:
When an organization needs to send up to millions of messages per hour, or needs deep integration in a modern DevOps environment, but doesn't want to be bound by restrictive license agreements and mandatory annual fees.
KumoMTA's answer:
KumoMTA's answer:
High-volume multi-tenant senders.
KumoMTA might be a bit more popular than Postfix. We know about 1 link to it since March 2021 and only 1 link to Postfix. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Read the documentation on postfix.org and/or buy one of the many available Postfix books (it really helps to understand the Postfix philosophy). Source: about 3 years ago
I've been using KumoMTA for the past 3 months and it's one of the most well thought-out, stable and fast softwares I've ever used. https://kumomta.com/. - Source: Hacker News / about 2 months ago
iRedMail - A fully fledged, free email server solution, an open source project (GPL v2).
PowerMTA - PowerMTA is an industrial-strength software for high-volume email delivery.
Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.
MailerQ - MailerQ is a high performance Mail Transfer Agent (MTA) designed for delivering large volume email messages at very high speeds.
Exim - Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.
Halon MTA - Scriptable and scalable SMTP server and email framework designed for service providers.
