KumoMTA vs MailerQ (2026): which should you pick?
As of Nov 13, 2026, KumoMTA grades higher than MailerQ: 2.2 against 1.6 out of 4.0.
Checked Nov 13, 2026 · graded Nov 13, 2026 by ToolGPA
KumoMTA grades higher on value for money and the free plan. They get the same grade on features, ease of use and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
KumoMTA
Open-source mail server for high-volume, self-run email sending
MailerQ
Self-hosted mail transfer agent for high-volume email sending
Which one is for you
Pick KumoMTA if
- Fits if you're an engineering team running your own high-volume sending
- Works for senders moving off a commercial mail server who can write Lua
Look elsewhere if
- Skip it if you want a point-and-click setup, since configuration is done in Lua
- Tight if you need support: Silver is business hours only, and Enterprise has no published price
- Not for you if you want a hosted service, as you run it yourself
- Watch out: the pages don't say which operating systems are supported
Pick MailerQ if
- Fits if you send millions of emails and run your own sending servers
- Makes sense if you want a console to manage IP warm-up and per-provider limits
Look elsewhere if
- Skip it if you want a hosted service, as it's software you install and run
- Pricey if you're small: €10,000 up front and €2,000 a year after
- Tight if you send a lot on Regular, which stops at 100K emails an hour and 10 domains
- Watch out: the trial length isn't stated, and the pages don't name supported operating systems
How we grade them
| 2.2GPAKumoMTAFair | 1.6GPAMailerQWeak | |
|---|---|---|
| Value for money | CThe software is free under Apache 2, but you host it yourself, and paid support starts at $5,000 per billion messages a year. | D€10,000 one-time per instance, plus €2,000 a year for updates and support. That's many years of the category's middle subscription at $15 a month, though it's a different kind of product from most of the category. |
| Free plan and trial | BEvery feature is free to run, with community help on Discord. You do need your own server to use any of it. | DA trial license is available on request, with the length not stated. |
| Features | BHigh-volume sending, Lua policy scripting, traffic shaping and IP pools, with hooks into Kafka, AMQP, Prometheus, Grafana and Vault. Nothing in the listing shows a gap in the job. | BManagement console, throttling, IP warm-up schedules, bounce and feedback handling, authentication and a REST API. Nothing in the listing is missing from the job of a mail transfer agent. |
| Ease of use | DNo store rating on record. It's configured in Lua scripting on your own servers, so it suits engineers. | DNo store rating on record. It's installed on your own servers and uses RabbitMQ and a MySQL or PostgreSQL database. |
| Platforms and integrations | CSoftware for your own servers, listed for Linux, with Docker and Kubernetes. No dashboard or hosted version. | CSoftware for your own servers with a REST API and injection methods. The pages don't name supported operating systems. |
| Best for | a free high-volume mail server you run yourself | a self-run mail server for very large senders |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: KumoMTA and MailerQ. How we grade
Where they differ
- KumoMTA is open source, according to its own site.
- MailerQ also covers inbox warm-up and dMARC.
At a glance
| KumoMTA | MailerQ | |
|---|---|---|
| Pricing | Free plan | Free trial |
| Starts at | $5,000 per billion messages per year for Silver support | €10,000 one-time per instance, plus €2,000 a year for updates and support |
| Free plan | The software and all its features are free under the Apache 2 license; community support runs through a Discord server. | None |
| Free trial | None listed | Free trial license available on request from the site; length not stated. |
| Web | ||
| Linux | ||
| Made by | Kumo Corp | Copernica BV |
| Price read from | kumomta.com | mailerq.com |
| Checked | Nov 13, 2026 | Nov 13, 2026 |
Worth knowing
KumoMTA
- It is software you run yourself on your own servers; the pages do not say which operating systems are supported.
- Support is priced per billion messages a year with no server limit; Silver is business hours only, and Enterprise has no published price.
- Configuration is done in Lua scripting, so it suits engineers, not a point-and-click setup.
MailerQ
- It is software you install and run on your own servers; the vendor describes it as on-premise, and it uses RabbitMQ and a MySQL or PostgreSQL database.
- Prices are in euros, per instance. Updates and support are an extra yearly charge of 20% of the license fee.
- The Regular license caps sending at 100K emails per hour and 10 domains.
- The pages do not name supported operating systems.
Key features
KumoMTA
- High-volume sending
- The vendor says a single server can send several million messages an hour, and that it can scale out with Docker and Kubernetes.
- Lua policy scripting
- Behavior is set in Lua scripts, with policy helpers for common configurations.
- Integrations for operations
- Supports webhooks, AMQP, Kafka, Vault, Prometheus, Grafana and direct database access.
- Traffic shaping and IP pools
- A customer quote on the site names traffic shaping and IP pool automation as the parts it builds on.
- Migration guides
- The site has a migration center with pages for moving from Momentum, PowerMTA, Halon, SendGrid and Hurricane MTA.
- Open source
- Released under the Apache 2 license, with the source code on GitHub.
MailerQ
- Management console
- A web console shows delivery attempts, queues, error logs and statistics per IP, target domain or tag, and lets you change deliverability settings.
- Throttling and flood patterns
- Sets delivery rates for each source IP and target domain, and slows or pauses sending when a receiving server answers with rate-limit messages.
- IP warm-up schedules
- Throttle schedules define the sending rate to use on each day for a new IP address.
- Bounce and feedback processing
- Response patterns classify bounces, process feedback loops and trigger follow-up actions such as retrying or failing a delivery.
- Email authentication
- Supports DKIM, SPF, DMARC, TLS and ARC, according to the vendor.
- REST API and injection methods
- Messages can be injected in five ways, including AMQP, and a REST API can pause or cancel selected deliveries.
Plans
KumoMTA
Community$0
Free software with every feature. Help comes from the community Discord server; you host it yourself.
Silver$5,000
per billion messages per year
Business-hours support (9-5 US Eastern) by email and portal, a shared sponsor Discord channel and help with basic configuration.
Gold$10,000
per billion messages per year
Support 8-7 US Eastern, a 24/7 critical-issue SLA, a private Discord and help with custom Lua policy.
EnterpriseCustom
24/7/365 support, telephone support, a private Discord or Slack channel and refactored policy scripts. No price is stated; contact the vendor.
MailerQ
Regular€10,000
one-time fee per instance
Perpetual license: 100K emails per hour, 10 domains, management console. Updates and support cost €2,000 a year.
Enterprise€25,000
one-time fee per instance
Perpetual license: unlimited emails per hour and domains, management console. Updates and support cost €5,000 a year.
Common questions
Which is cheaper, KumoMTA or MailerQ?
As of Nov 13, 2026, KumoMTA starts at $5,000 per billion messages per year for Silver support, and MailerQ starts at €10,000 one-time per instance, plus €2,000 a year for updates and support.
Which has a free plan, KumoMTA or MailerQ?
As of Nov 13, 2026, only KumoMTA has a free plan. MailerQ does not, though it has a free trial.
Which platforms do KumoMTA and MailerQ run on?
As of Nov 13, 2026, only KumoMTA lists a Linux app and only MailerQ lists a web app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.