Is there a free open source alternative to Mailchimp?

Yes. MagpieCRM, listmonk, Mautic and Keila are all free to self-host. You pay only for your server and for sending, for example $0.10 per 1,000 emails through Amazon SES.

Can I send email marketing from my own server?

You can run the marketing software on your own server, but you should send through a delivery service such as Amazon SES, Postmark or an SMTP relay. A new mail server has no reputation, so its email is likely to land in spam.

What is the cheapest way to send marketing email?

Self-hosted software sending through Amazon SES, at $0.10 per 1,000 emails. For 100,000 emails a month, that is about $10 in sending costs, plus a small server.

Is self-hosted email marketing GDPR compliant?

Self-hosting helps, because subscriber data stays on servers you choose. You still need a lawful basis for sending, clear consent records, a working unsubscribe and a data processing agreement with your sending service.

Open Source Email Marketing Software (Self-Hosted)

The short version

Open source email marketing software lets you build lists, segments and campaigns on your own server, then send through a service you choose, such as Amazon SES at $0.10 per 1,000 emails.
You still need a sending service and SPF, DKIM and DMARC records. Self-hosting does not mean running a mail server.
MagpieCRM includes email and SMS flows on the same database as your CRM, so segments use live deal and contact data.
Standalone options: listmonk for newsletters, Mautic for automation and Keila for a simple Mailchimp-style tool.

What is open source email marketing software?

Open source email marketing software is a newsletter and campaign tool whose code is published under an open source license. You can run it on your own server and change how it works. It handles lists, segments, templates, campaigns, automated flows, and open and click tracking.

The actual delivery goes through an email service you connect. That split is what makes it cheap. The software is free, and you pay the sending service per email.

Hosted tools such as Mailchimp and Klaviyo work differently. They price by the number of contacts you store, so the bill grows with your list whether or not you email those people. With self-hosted software:

You pay for the emails you send, not the contacts you keep.
Your subscriber data stays in your own database.
You can pick, and switch, your sending service at any time.
There are no seat limits, so the whole team can log in.

How does self-hosted email sending work?

Self-hosted email marketing sends through a delivery service, not your own mail server. The marketing software runs on your server and builds each email. A service such as Amazon SES then delivers it. New mail servers have no reputation, so big inboxes treat them with suspicion.

Amazon SES costs $0.10 per 1,000 emails, according to the Amazon SES pricing page. It is the cheapest option at volume, with some setup in AWS.
Postmark, Resend and other API services cost more per email, with simpler setup.
Any SMTP relay, including Google Workspace or Microsoft 365 for small volumes. Both limit daily sends and are not built for bulk email.

On Magpie Cloud, sending through SES is set up for you. 100,000 emails sent a month comes to £15.00 on Magpie Cloud, for the whole team.

How do you keep self-hosted email out of spam?

You keep self-hosted email out of spam by proving you own your domain, growing volume slowly and removing bad addresses fast. The standards below tell inbox providers who you are. Gmail and Yahoo now require them for bulk senders.

Send from your own domain, with SPF, DKIM and DMARC records.
Warm up new domains and IP addresses. Do not send your whole list on day one.
Remove hard bounces at once, and suppress anyone who unsubscribes or complains.
Add one-click unsubscribe to every marketing email.
Send marketing from a subdomain, so a bad campaign cannot hurt your everyday email.

Watch your spam rate. Google's sender guidelines say to keep it below 0.10% and never let it reach 0.30%. They also require one-click unsubscribe if you send more than 5,000 messages a day.

On Magpie Cloud, sending domains and IP addresses rotate by themselves to protect your reputation. You only add a few DNS records.

What are the best open source email marketing tools?

The best open source email marketing tools in 2026 are MagpieCRM, listmonk, Mautic and Keila. We compared each one on 26 September 2026, using its own website, docs and code repository. They suit different jobs, from simple newsletters to full marketing automation.

MagpieCRM

We built MagpieCRM so marketing runs on the same data as sales. You design email and SMS flows with splits and delays, and start them from any CRM event, such as a signup or a deal stage change. It sends through SMTP, Amazon SES, Postmark or Resend, with A/B tests and per-step stats.

listmonk

listmonk is a fast newsletter tool written in Go on Postgres, licensed AGPL-3.0. It handles very large lists, and can send SMS or WhatsApp through webhooks. It has no CRM and no multi-step flows.

Mautic

Mautic is the best-known open source marketing automation platform, licensed GPL-3.0 and built on PHP. It has segments, lead scoring, forms, landing pages and campaigns. It has no deal pipeline.

Keila

Keila is a simple newsletter tool written in Elixir on Postgres, licensed AGPL-3.0. It has a hosted plan from €8 a month.

Mailtrain was once popular, but its last release was in 2021. Sendy is often listed too, but it is not open source. It is a paid, closed app you host yourself.

Open source email marketing comparison

The table compares the self-hosted edition of each open source email marketing tool. It focuses on what separates them: automated flows, SMS, and whether the tool includes a CRM.

Checked 26 September 2026.
	MagpieCRM	listmonk	Mautic	Keila
License	AGPL-3.0	AGPL-3.0	GPL-3.0	AGPL-3.0
Database	Postgres	Postgres	MySQL / MariaDB	Postgres
Automated flows	Yes	No	Yes	No
SMS	Yes	Via webhooks	Yes	No
CRM and deals	Yes	No	Contacts only	No
Sales sequences	Yes	No	No	No
Hosted version	From £10/mo	No	No	From €8/mo

We found that the right choice depends on whether marketing needs sales data. If you only send a newsletter, listmonk or Keila is the simplest thing that works. If campaigns need to react to deals, a tool with a built-in CRM saves you from syncing two systems. That is how MagpieCRM is built.

Open source email marketing, connected to your CRM