Open Source Email Marketing Software: 15 Tools, Licenses and What Is Still Maintained

I build commercial email marketing software, so let me start with a correction. An earlier version of this page called Octeth open source. It is not. Octeth is commercial software with a free Community License. That mix-up is common across this topic: most lists of "open source email marketing software" include paid tools and projects that have not shipped a release in years.

So I rebuilt this page around three facts per tool, all checked on GitHub on 2026-10-03: the license, the latest release, and what the tool is really for.

Short answer

If you need	Open source pick
A fast, free newsletter sender	listmonk (AGPL-3.0)
Full marketing automation with lead scoring and landing pages	Mautic (GPL-3.0)
A clean Mailchimp-style newsletter tool	Keila (AGPL-3.0)
A long-running PHP list manager	phpList (AGPL-3.0)
A mail server plus bulk sender in one stack	BillionMail (AGPL-3.0)
Product and transactional email with light campaigns	Plunk (AGPL-3.0)
Event-driven journeys across email, SMS and push	Dittofeed (MIT, open core)
Campaigns inside WordPress	MailPoet (GPLv3), FluentCRM (GPLv2+)
Many client accounts, white-label and vendor support	Not available as open source. Look at commercial self-hosted platforms such as Octeth

Open source, free and self-hosted are three different things

Open source describes the license: you can read, modify and redistribute the code under its terms. Free describes the price. Self-hosted describes where the software runs. A tool can be any combination of the three. listmonk is all three. Sendy and MailWizz are self-hosted but commercial. Mailchimp's free plan is free but neither open source nor self-hosted.

The license matters most if you plan to modify the code or offer it to others. Most tools here use the AGPL-3.0: if you modify the software and let other people use it over a network, you must publish your changes under the same license. Running it unmodified for your own sending carries no such duty. MIT and LGPL are more permissive. "Open core" means the base is open source and some features, often multi-tenancy or white-label, are closed and paid.

The 15 tools compared

Checked on GitHub and the official sites on 2026-10-03.

Newsletter and bulk senders

listmonk. A single Go binary with PostgreSQL. It is very fast and light, with SQL-based segmentation, a transactional API, roles and SSO, and support for multiple SMTP servers. It has 23,000+ GitHub stars and active commits. It has no automation journeys. For most developers who want a free newsletter sender, this is the default choice.

Keila. A Mailchimp-style tool from Germany in Elixir. It has a block editor, a visual segment editor, forms with double opt-in and an API. It sends through SMTP, Amazon SES, SendGrid, Mailgun or Postmark. Client sub-accounts exist only in the hosted Keila Cloud.

phpList. One of the oldest PHP list managers and still released regularly. It has strong bounce processing, per-domain throttling, RSS-to-email and built-in Amazon SES support. The interface is dated and it has no journeys.

BillionMail. A Docker stack that bundles Postfix, Dovecot and Rspamd with a campaign sender, so you can send from your own IPs. It has 15,000+ stars. The last commit was in June 2026. Sending from your own IPs makes the deliverability work entirely yours.

OpenEMM. The free edition of AGNITAS's commercial E-Marketing Manager, written in Java with its own Postfix-based mail backend. It is mature and actively released, with a commercial upgrade path. It needs RHEL-family Linux and Java skills.

Marketing automation and journeys

Mautic. The most complete open source marketing automation suite: a campaign builder with decisions, lead scoring, landing pages, forms, web tracking and A/B tests. It is also the heaviest to run. The project advises against shared hosting.

Dittofeed. Event-based journeys across email, SMS, push and Slack, built for product teams with event data. The core is MIT-licensed. Multi-tenancy, embedding and white-label are in a closed, licensed codebase.

Plunk. Transactional email, campaigns and simple workflows in one AGPL project. Self-hosting requires Amazon SES credentials.

Inside an app you already run

MailPoet and FluentCRM run inside WordPress, and MailPoet adds WooCommerce automations. Odoo Email Marketing is an LGPL module of Odoo Community. Its marketing automation module is Enterprise-only. EspoCRM and SuiteCRM are AGPL CRMs with campaign and mass email modules, suited to occasional campaigns to CRM contacts rather than high-volume sending.

Stale or discontinued

SendPortal (MIT, Laravel) has had no release since April 2024. Mailtrain has had no release since June 2021, although many lists still rank it near the top. Laudspeaker's README says it is no longer under active development. A tool that has stopped shipping will fall behind Gmail and Yahoo sender requirements, so check the last release before you install.

Often called open source, but commercial

These tools appear in most "open source" lists. They are self-hosted, but their licenses are commercial:

For a full comparison of self-hosted tools regardless of license, see our self-hosted email marketing software guide.

When open source is not enough

Open source email marketing works well for one organization sending its own mail. It gets harder in three situations.

1. You send for clients. None of the maintained open source tools offers real multi-tenancy with per-client branding, limits and billing in its open edition. Keila keeps client accounts in its cloud, and Dittofeed keeps multi-tenancy in its closed edition. Our white-label email marketing guide covers the options.
2. You need someone to call. Community forums are helpful but carry no obligation. If an outage or a blocklisting costs you money, a vendor relationship is often cheaper than the time it takes to fix it yourself.
3. You send at high volume across several delivery servers. You need routing per client or per channel, bounce and feedback-loop processing at scale, and warm-up for new IPs.

This is where Octeth fits. It is commercial software, built for agencies and high-volume senders:

1. Multi-client accounts with their own branding, lists, limits and delivery servers.
2. Full white-label on your own domain.
3. Journeys with email and SMS steps, decision branches and webhooks.
4. Delivery routing across Amazon SES, Mailgun, SendGrid, PowerMTA or any SMTP server.
5. Installation, onboarding and support from the team that builds it.

If you are one organization sending your own newsletter, listmonk, Keila or Mautic will serve you well for free.

What you need to self-host any of them

1. A Linux server sized for your list: about 2 vCPU and 4 GB RAM for 10,000 subscribers, 4 vCPU and 8 GB for 100,000.
2. A database, a queue worker and scheduled jobs.
3. DNS for your sending domains: SPF, DKIM and DMARC. Our free SPF generator, DKIM generator and DMARC generator produce the records.
4. A delivery path: a relay such as Amazon SES (the safe default), or your own MTA with warmed-up IPs. The IP warm-up planner schedules new IPs.
5. Bounce and complaint processing, backups and an update routine.

Frequently asked questions