Assembly Line

BillionMail vs Mailchimp

BillionMail and Mailchimp are both email marketing software. BillionMail is open source under AGPL-3.0, with 16k GitHub stars. Mailchimp is a commercial product from Intuit.

Which to pick

Pick BillionMail when
You want to run your own mail server and campaigns together and know how to manage IP reputation.
Pick Mailchimp when
A small business or nonprofit wants a familiar email newsletter tool with lots of templates.

Side by side

What it does

Bundles a mail server (Postfix, Dovecot, Rspamd) with newsletter and email marketing tools in one self-hosted package.

Email marketing with templates, audience segmentation, automations, landing pages and basic e-commerce integration, owned by Intuit.

Watch out

Running your own outbound mail server is hard to get delivered; activity slowed after June 2026.

Prices have risen and the free plan has shrunk, while competitors offer more automation per dollar.

Ready for

Usable

Production-ready

Runs as

Self-hosted server

Cloud service and mobile app

Built with

Go, PostgreSQL, Redis, Postfix, Dovecot and Rspamd

Not published

Source code

Open source, AGPL-3.0 (network copyleft)

Closed source, sold by Intuit

What the license allows

Use inside your business is unrestricted. If you change it and let customers use it over the internet, you must publish your changes.

Closed source: you use it under the maker's terms and cannot change or resell the code.

How widely known

16k GitHub stars

1k Wikipedia readers a month on phones

How established

Young: started 20 months ago, latest release v4.9.

Not known

Other comparisons

More email marketing and newsletter software

Every email marketing product and project, ranked

Both sides were judged on 2026-11-03 from makers' descriptions, Wikipedia, READMEs and GitHub data. License, age and popularity lines are worked out directly.