Open source email newsletter and marketing tools

Four kinds of newsletter tool

The apps in this category do overlapping but different jobs, so start by deciding which one you need.

• List and campaign managers store subscribers, handle signups and unsubscribes, and send newsletters and campaigns. listmonk, Keila, phpList and SendPortal belong here. They are the closest match to the everyday use of Mailchimp.
• Marketing automation adds multi-step journeys, lead scoring, forms and landing pages. Mautic is the established open source option and covers the automation side of Mailchimp and Kit.
• Publishing platforms tie email to a website, member accounts and paid subscriptions. Ghost works this way, like Substack, and is the option for writers who want to charge readers.
• Developer email platforms combine a transactional email API with contact lists and campaigns. Plunk and useSend suit software products that send receipts and onboarding mail as well as product updates. BillionMail goes further down the stack and bundles its own mail server with a campaign interface.

Sending and deliverability

Most of these tools do not deliver mail themselves. They hand messages to an SMTP server or an email sending provider, and that choice decides much of your deliverability and running cost. Check which providers each tool supports: listmonk, Keila, Mautic and SendPortal work with many, Ghost sends newsletters only through Mailgun, and Plunk and useSend are built on Amazon SES. Running your own mail server, as BillionMail does, gives full control but makes IP reputation, blocklists and blocked port 25 your problem.

Mailbox providers have tightened their rules for bulk senders. Google requires anyone sending more than 5,000 messages a day to Gmail accounts to authenticate with SPF, DKIM and DMARC, support one-click unsubscribe through the List-Unsubscribe headers defined in RFC 8058, and keep the spam rate reported in Postmaster Tools below 0.30%. Yahoo sets similar conditions and asks senders to honor unsubscribes within two days. Look for a tool that adds these headers and processes bounces and complaints automatically, and set up the DNS records for your sending domain before you migrate a large list.

Consent and the law

In the EU, Article 13 of the ePrivacy Directive allows marketing email only to people who have given prior consent. The one exception is a business that collected a customer’s address during a sale: it may promote its own similar products, as long as the customer can object easily and free of charge when the address is collected and in every message. Double opt-in, where a new subscriber confirms through a link, is the usual way to prove consent; listmonk, Keila and useSend support it.

In the United States, the FTC’s CAN-SPAM guidance requires honest headers and subject lines, a valid postal address, a working opt-out and that opt-out requests are honored within 10 business days, with no exception for business-to-business email. Neither law depends on the software you use, but a tool with signup forms, opt-in records and reliable unsubscribe handling makes compliance much easier.

Privacy and tracking

Open tracking relies on a pixel in each message and click tracking rewrites links, both of which record what individual readers do. If you want to minimize that, listmonk can disable tracking or keep it anonymous, Keila can switch it off entirely, and Plunk can turn it off or limit it to marketing mail. Self-hosting keeps the subscriber list on your own server, although your sending provider still processes every address.

What to check before you choose

1. The job. Newsletters only, automated journeys, paid subscriptions, or product email from an app.
2. Sending. Supported providers, bounce and complaint handling, and one-click unsubscribe.
3. Self-hosting effort. listmonk is a single binary with PostgreSQL; Mautic, phpList and SendPortal are PHP applications that need cron jobs; Plunk and useSend run several services.
4. Migration. All of them import CSV files. Ghost also has importers for Substack posts and members and for Mailchimp members, and paid Substack subscribers can continue when you connect the same Stripe account.
5. Hosted options. Ghost, Keila, phpList, Plunk and useSend have a hosted service from the developers; Mautic hosting comes from partners.

Projects we do not list

Notifuse moved to the Business Source License from version 40, so current releases are source-available rather than open source. Mailtrain is GPL-licensed but has had no commits since 2022. MailPoet, a GPL WordPress plugin, caps the free version at a number of subscribers in its code and needs a paid plan beyond that. Postal is open source sending infrastructure rather than a newsletter tool, and SendPortal can use it to deliver mail.