Email marketing remains the highest ROI channel for small businesses – but most platforms (Mailchimp, ConvertKit, ActiveCampaign) charge per subscriber. As your list grows, your bill skyrockets. A list of 5,000 subscribers can easily cost $100+ per month.
Open source email marketing solutions flip the model. Pay only for your hosting (a fixed monthly cost) and send unlimited emails to unlimited subscribers. Here are five powerful open source tools you can self‑host.
SolOPENpreneur comes with Mautic – enterprise‑grade marketing automation, self‑hosted.
Start email marketing →Mautic is the leading open source marketing automation platform. It's used by companies like Tesla and NBA – but it's free (as in freedom) for anyone. Features include:
Best for: Solopreneurs who need serious marketing automation without paying $500+/month.
Replaces: HubSpot Marketing Hub, ActiveCampaign, Mailchimp Pro.
Listmono is a minimalist email newsletter system inspired by Mailchimp but self‑hosted. It's written in PHP and designed to be easy to install on any VPS.
Best for: Solopreneurs who just need basic newsletter sending without complex automation.
Replaces: Mailchimp Free tier, TinyLetter, Sendy (self‑hosted).
Sendy is a self‑hosted email newsletter application that sends via Amazon SES (Simple Email Service). SES costs roughly $0.10 per 1,000 emails – that's 10x cheaper than Mailchimp. Sendy provides the interface and subscriber management.
Best for: Solopreneurs sending high volumes of email (e.g., daily newsletters, deal alerts).
Replaces: Mailchimp paid plans, Constant Contact.
Note: Sendy is not free (one‑time $69 license) but still far cheaper than monthly SaaS.
PHPList has been around for over 15 years. It's battle‑tested, reliable, and focused on one thing: sending newsletters to large lists. It's not as pretty as modern tools, but it works.
Best for: Solopreneurs with large lists (10k+ subscribers) who need reliable delivery.
Replaces: Mailchimp Pro, Campaign Monitor, AWeber.
Mailtrain is built on Node.js and is modern, fast, and feature‑rich. It supports list management, campaigns, automations, and analytics.
Best for: Tech‑savvy solopreneurs who want modern features with full control.
Replaces: ConvertKit, MailerLite, Drip.
If you're using SolOPENpreneur, you already have Mautic pre‑installed. Start there – it's powerful enough for most solopreneurs and integrates perfectly with n8n and ERPNext.
Let's compare a list of 5,000 subscribers:
That's $900‑$1,200 saved per year. And as your list grows to 50,000, SaaS prices jump to $200‑$500/month. Self‑hosted stays flat.
Get Mautic pre‑installed, fully managed, and integrated with your entire business stack.
Start your free consultation →Next in our series: Growing Your Solo Entrepreneur Business with Open Source Software: Tips and Tricks – coming soon.
See exactly how much a solopreneur overpays for 16 SaaS subscriptions every year, and the open source stack that replaces them for one flat price. Plus occasional open source growth tips. No spam, unsubscribe anytime.