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Open source Mailchimp alternatives come down to three: listmonk for newsletters, Mautic for marketing automation, and Keila as a lighter middle option. All three are free to license and none are free to run, because you supply the server and an email delivery service. This page is for people who want to self-host. If you would rather not, the hosted free option is at the end, and it pays this site a commission where the open source tools do not.
The three open source options
| Tool | Best for | What it needs |
|---|---|---|
| listmonk | Newsletters and mailing lists at scale | A server, PostgreSQL, and an SMTP or API sender |
| Mautic | Automation, lead scoring, campaigns | A PHP server, a database, more upkeep |
| Keila | A simpler newsletter tool with a modern UI | A server and a sending service |
listmonk ships as a single binary and handles large lists on small hardware. Mautic is the closest thing to a full marketing platform and needs the most attention. Keila sits between them.
What self-hosting costs
The licence is free. The rest is not:
- A server: from a few dollars a month for a small instance.
- A sending service: Amazon SES, Postmark, or similar, priced per thousand emails. You cannot send bulk mail from a bare server and reach the inbox.
- Domain authentication: SPF, DKIM, and DMARC set up correctly, or nothing lands.
- Time: updates, backups, bounce handling, and the evening it breaks.
For a technical person with an existing server, that is cheaper than any paid plan past a few thousand contacts. For anyone else, the hours cost more than the subscription.
When hosted free beats self-hosted
If the list is under 2,000 contacts and you want landing pages, a checkout, or automations without running a server, systeme.io’s free plan sends unlimited emails with deliverability handled for you. It is not open source and you do not own the infrastructure, which is the trade.
Who should self-host
Developers, privacy-focused organisations, and anyone with a list large enough that per-contact pricing hurts. If you read “SPF, DKIM, and DMARC” without flinching, listmonk is the pick.
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Frequently asked questions
What is the best open source Mailchimp alternative?
listmonk for newsletters and Mautic for marketing automation. Keila is a lighter option with a modern interface.
Is listmonk free?
The software is free and open source. You pay for a server and an email sending service.
Can I self-host Mailchimp?
No. Mailchimp is a hosted service. The self-hosted equivalents are listmonk, Mautic, Keila, and similar projects.
Do I need an SMTP service with listmonk?
Yes. listmonk manages lists and campaigns; delivery goes through a provider like Amazon SES or Postmark.
Related: free Mailchimp alternatives, systeme.io pricing.