KumoMTA vs MailChannels (2026): which should you pick?
As of Nov 13, 2026, MailChannels grades higher than KumoMTA: 2.8 against 2.2 out of 4.0.
Checked Nov 12, 2026 and Nov 13, 2026 · graded Nov 12, 2026 and Nov 13, 2026 by ToolGPA
MailChannels grades higher on value for money, ease of use and platforms. They get the same grade on the free plan and features.
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
MailChannels
Email API and SMTP relay for platforms with many downstream senders
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 MailChannels if
- Fits if you run a platform that sends mail for many customers
- Works for developers who want a free tier to prototype on
Look elsewhere if
- Skip it if you want email support on a small plan, as it is listed only from 300,000 emails a month
- Tight if you stay free, because it stops at 100 emails a day with no overage
- Watch out: the page says no tier sits between the free plan and the 10,000-email paid plan
- Watch out: Outbound Filtering for hosting providers is a separate product from $99.99 a month
- Not for you if you want open and click tracking for free, as it comes with the paid plan
How we grade them
| 2.2GPAKumoMTAFair | 2.8GPAMailChannelsGood | |
|---|---|---|
| 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. | B$10 a month for up to 10,000 emails, the top of the category's cheaper quarter, rising to $30 at 100,000. |
| 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. | B3,000 emails a month, 100 a day, 3 domains and no overage charges, which a small project can live on, though open and click tracking need a paid plan. |
| 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. | BA REST API and SMTP, per-tenant sub-accounts, bounce and complaint webhooks, threat filtering and approval hooks. The core sending job is covered. |
| Ease of use | DNo store rating on record. It's configured in Lua scripting on your own servers, so it suits engineers. | CNo store rating on record. You verify a sending domain with DNS records and wire up SMTP credentials or an API key before the first email goes out. |
| Platforms and integrations | CSoftware for your own servers, listed for Linux, with Docker and Kubernetes. No dashboard or hosted version. | BA web console and an API; the listing names Laravel, Symfony, Nodemailer, Django, FastAPI and cPanel. |
| Best for | a free high-volume mail server you run yourself | platforms that send mail for many customers |
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 MailChannels. How we grade
Price against what you get
KumoMTA starts at $416.67 a month when paid by the year and scores 2.0 out of 4 on features, ease of use and platforms. MailChannels starts at $10 a month and scores 2.7.
MailChannels scores higher and starts $406.67 a month lower. Of the other email sending services on the chart, 30 score higher than KumoMTA for less, and none scores higher than MailChannels for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- KumoMTA is open source and self-hostable, according to its own site.
At a glance
| KumoMTA | MailChannels | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $5,000 per billion messages per year for Silver support | $10 per month for 10,000 emails, billed monthly |
| Free plan | The software and all its features are free under the Apache 2 license; community support runs through a Discord server. | Up to 3,000 emails a month and 100 a day, no overages, 3 domains, 30-day logs and community support. |
| Free trial | None listed | None listed |
| Web | ||
| Linux | ||
| Made by | Kumo Corp | MailChannels Corporation |
| Price read from | kumomta.com | mailchannels.com |
| Checked | Nov 13, 2026 | Nov 12, 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.
MailChannels
- The free plan has no overages and stops at 100 emails a day.
- The page says there is no tier between the free plan and the 10,000-email paid plan.
- Email support is listed only for plans of 300,000 emails a month and up; lower plans list community support.
- Outbound Filtering for hosting providers is a separate product, from $99.99 a month for 40,000 emails.
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.
MailChannels
- REST API and SMTP relay
- Mail goes out through a REST API or an SMTP relay with the same controls on either path.
- Sub-account isolation
- Each tenant, workspace or AI agent gets its own sender identity, with reputation, limits and policy scoped to it.
- Bounce and complaint webhooks
- Webhooks report delivery events, including feedback-loop complaints, so a platform can retry, pause or suspend a single sender.
- Inline threat filtering
- Outbound messages are scanned for phishing, malware and known abuse patterns before they leave the network.
- Approval hooks for agents
- A human or programmatic checkpoint can be placed in the send path, which the vendor suggests for AI agents sending high-risk messages.
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.
MailChannels
Free$0
Up to 3,000 emails a month and 100 a day, REST API and SMTP, up to 3 domains and community support.
Pay as You Grow$10
per month for up to 10,000 emails, billed monthly
Adds open and click tracking and up to 1,000 domains. Price rises with volume: $30 a month at 100,000 emails, $300 at 1,000,000.
CustomCustom
For 1,500,001+ emails a month, with custom policies and domain limits. Contact sales.
Common questions
Which is cheaper, KumoMTA or MailChannels?
As of Nov 13, 2026, MailChannels is cheaper to start with: $10 a month, against $416.67 a month when paid by the year for KumoMTA. KumoMTA starts at $5,000 per billion messages per year for Silver support, and MailChannels starts at $10 per month for 10,000 emails, billed monthly.
Which has a free plan, KumoMTA or MailChannels?
As of Nov 13, 2026, both KumoMTA and MailChannels have a free plan.
Which platforms do KumoMTA and MailChannels run on?
As of Nov 13, 2026, only KumoMTA lists a Linux app and only MailChannels 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.