Open source communities are built on trust. People contribute their time, their code, their expertise—for free—because they believe in the project and its mission. Email marketing in this context isn't really marketing at all. It's community communication, and if you approach it with typical marketing tactics, you'll destroy the very thing that makes open source communities valuable.

I've watched companies build thriving open source projects with engaged email audiences, and I've watched others burn community goodwill faster than they built it. The difference always comes down to understanding what open source really is: a relationship based on mutual value, transparency, and shared purpose. Your email program should reflect that, or you shouldn't have one at all.

This guide is for anyone building email communication around an open source project—whether you're a solo maintainer running a passion project, or a company trying to build a sustainable business around open source software. The principles apply regardless of scale, though the specifics change based on your goals.

Two Different Email Worlds: Community vs. Commercial

Before we go further, let's be clear about what we're talking about. Open source email communication typically falls into two distinct categories, and conflating them is where most problems start.

Email Type	Purpose	Audience	Tone	Commercial Content
Community Updates	Project news, roadmap, releases	All community members	Collaborative, inclusive	Never
Contributor Comms	Recognition, coordination, opportunities	Active contributors	Appreciative, personal	Never
User Onboarding	Help with adoption	Users implementing the project	Helpful, technical	Minimal mentions only
Product Newsletter	Commercial offering updates	Opt-in commercial interest	Professional, value-focused	Yes, clearly
Sponsorship Asks	Funding sustainability	Supporters who opted in	Honest, transparent	Yes, it's the point
Open-Core Upgrades	Paid tier promotion	Users of commercial layer	Respectful, benefit-focused	Yes, clearly

The fundamental principle: never mix community communication with commercial promotion. Keep them separate. Different lists, different sending addresses, different opt-ins. When someone joins your community mailing list, they're trusting you with their attention for community purposes—using that access for sales pitches is a betrayal of that trust.

This might seem obvious, but it's where most open source email programs go wrong. A project starts with a community newsletter. It grows. The company wants to monetize. Someone decides to "leverage the existing list" for commercial announcements. The community notices. Trust erodes. The list becomes less valuable than if they'd just built a separate commercial list from scratch.

Community Updates That Strengthen Participation

Community updates are the lifeblood of open source email communication. Done well, they make people feel connected to the project even when they're not actively contributing. Done poorly, they're ignored noise that eventually leads to unsubscribes.

What makes a great community update:

The best community updates make readers feel like insiders, not outsiders. They share the actual state of things—what's working, what's challenging, where the project is headed. They don't sanitize everything into corporate-speak. Open source thrives on transparency, and your emails should reflect that.

Share the roadmap, including uncertainties. "We're considering two approaches for the new caching layer. Option A gives us X but complicates Y. Option B is simpler but might limit Z. Here's our current thinking, and we'd love community input." This is infinitely more engaging than "Exciting developments coming soon!"

Celebrate community contributions publicly. Name the people who made things happen. Link to their contributions. Show that you notice and value what they do. This recognition costs you nothing but means a lot to contributors, and it signals to potential contributors that their efforts will be seen.

Be honest about challenges. "We're struggling to find maintainers for the Windows compatibility layer. If anyone has expertise and time, here's how to get involved." Honesty about struggles brings solutions. Pretending everything is fine just makes you look disconnected.

Keep technical detail appropriate. Your community emails should be accessible to users who don't contribute code while still satisfying contributors who want technical depth. Often this means starting with a high-level summary and then providing links to deeper technical discussions for those who want them.

A community update structure that works:

Open with what's actually happening. Not pleasantries, not filler—the actual news. What shipped, what's in progress, what's being discussed. Then go into detail on the most significant items. Close with how people can get involved, and always include links to discussion forums, issues, or other places where conversation continues.

The frequency should match your actual development pace. Monthly works for many projects. Some active projects can sustain weekly. Others are better off with quarterly. Don't pad—if there's nothing meaningful to share, don't send an email just to maintain a schedule.

Contributor Emails: Recognition Without Cringe

Contributors are the lifeblood of open source. How you communicate with them through email matters enormously. Get it right and you deepen their connection to the project. Get it wrong and you make them feel like resources to be managed.

What contributors actually want:

Recognition that feels genuine. A personal thank-you for a significant contribution means more than a templated "Thanks for your pull request!" Generic automation feels like exactly what it is. Take time to acknowledge what specifically made their contribution valuable.

Efficient coordination. When you need to communicate about contribution logistics—review timelines, release schedules, coordination needs—be clear and respectful of their time. Contributors are volunteering; treating their time as precious demonstrates that you understand the nature of the relationship.

Insider access that means something. Early previews of upcoming features, input into roadmap decisions, invitations to contributor-only calls. These create a sense of belonging that strengthens commitment. But only do this if you actually value their input—performative inclusion is worse than no inclusion.

No guilt trips. Never email contributors to make them feel bad about reduced activity. Life happens. People step away. A contributor who takes a six-month break and comes back should feel welcomed, not interrogated about their absence.

Contributor milestone emails done right:

Many projects send automated emails for contributor milestones—first contribution, 10th contribution, and so on. These can be lovely or they can be cringe-inducing, depending on execution.

The good version: "Hey [name], I noticed this is your tenth contribution to [project]. I wanted to personally thank you—your work on [specific area] has made a real difference, particularly [specific impact]. If there's anything I can do to make contributing easier, let me know."

The bad version: "🎉 Congratulations! You've reached CONTRIBUTOR LEVEL 2! 🎉 Keep up the amazing work and unlock more achievements!"

The difference should be obvious. One treats the person as a valued collaborator. The other treats them like a player in a gamified system. Open source contributors aren't playing a game—they're building something they believe in.

The Commercial Conversion Conversation

Here's where it gets complicated. If you're running an open-core company or trying to build sustainable funding around an open source project, you need to think about commercial communication. But this needs to be handled with extreme care.

The foundational principle: always opt-in, always separate.

Someone who stars your GitHub repo hasn't opted in to commercial emails. Someone who joins your community Discord hasn't opted in to sales pitches. Someone who subscribes to release notifications definitely hasn't opted in to your enterprise sales funnel.

Commercial communication requires explicit, separate opt-in. "Yes, I want to hear about [Company]'s commercial offerings." This is separate from community subscription. This is basic respect for consent, and it's also just smart list management—people who didn't ask for commercial emails don't convert anyway.

What respectful commercial email looks like:

When someone has actually opted in to hear about your commercial offerings, communicate with the same transparency that defines open source culture.

Explain your model honestly. "We offer [open source project] under [license]. We fund ongoing development through [commercial offering], which adds [specific features] for teams that need them. Here's how the economics work."

Be clear about what's free and what's paid. Nothing erodes trust faster than hidden commercial hooks. If something requires the paid tier, say so upfront. If something will become paid in the future, announce it well in advance.

Lead with value, not scarcity. Don't manufacture artificial urgency. Don't create FOMO. Open source users are sophisticated—they'll see through it, and it makes you look desperate. Focus on explaining the genuine value of what you're offering.

Acknowledge the community's role. "This commercial tier exists because of the open source community that built [project]. A portion of revenue goes back into maintaining the open source core." If this is true, say it. If it's not true, that's a bigger problem than your email strategy.

Sponsorship Asks: Funding Without Groveling

Many open source projects rely on sponsorship to survive. Communicating about sponsorship through email requires balancing genuine need with dignity.

The right framing:

Sponsorship isn't charity. It's investment in software that sponsors depend on. Frame it that way: "If your business runs on [project], supporting its development helps ensure it continues to improve and remains secure. Here's how sponsorship works and what different tiers provide."

Be specific about how money is used. "Current sponsorship covers [X hours/month] of maintainer time. With additional support, we could [specific roadmap item] or [specific maintenance need]." Transparency about funding builds trust.

Offer value at different levels. Not everyone can afford $1000/month. Some contributors might sponsor $5/month because they believe in the project. Have tiers that work for different situations, and make every tier feel valued.

Don't overask. One or two sponsorship-focused emails per year is plenty. If you're emailing about sponsorship monthly, you're annoying people. And definitely don't put sponsorship asks in community update emails—keep them separate.

What not to do:

Don't guilt trip. "We've worked 200 unpaid hours this month" reads as a guilt trip even if it's true. Focus on the value you provide, not the sacrifice you make.

Don't threaten abandonment. "Without sponsorship, this project may not survive" might be true, but leading with catastrophe rarely motivates positive action. It just makes people feel bad about using your software.

Don't create awkward tiers. "MEGA SUPPORTER PLATINUM TIER" sounds silly. Just describe what different sponsorship levels provide and let people choose.

Practical Email Types for Open Source

Let me walk through the specific emails that make sense for most open source projects.

Release announcements: These should go to everyone who's opted in to release notifications. Be comprehensive—what's new, what's changed, what's deprecated, what's fixed. Link to full release notes. Keep it technical enough to be useful but accessible enough for users who don't dig into every commit.

Security advisories: These are critical. Use a distinct subject line format that's immediately recognizable. Include CVE numbers if applicable. Explain the impact, who's affected, and exactly what to do. These go to everyone—security is too important for opt-out.

Contributor recognition roundups: Monthly or quarterly recognition of community contributions. Name people, link to their work, express genuine appreciation. This email can also highlight open opportunities for contribution.

Roadmap updates: Share what's coming and invite feedback. These work well quarterly for most projects—frequently enough to keep people informed, infrequently enough that each one has substance.

Governance and decision communications: When there are significant governance decisions—new maintainers, policy changes, license considerations—communicate clearly and invite input. Open source governance should be open.

For more on technical email communication patterns, our developer tools email marketing guide covers many relevant principles.

What Never Belongs in Open Source Email

Some things should never appear in your open source communication, period.

Dark patterns of any kind. No artificial scarcity. No countdown timers. No "limited time offers" on sponsorship. This manipulative marketing garbage has no place in open source.

Purchased lists. Never email anyone who didn't explicitly sign up. Open source reputation is built on trust. Spam destroys it instantly.

Misleading metrics. Don't claim "10,000 companies use [project]" if you don't actually know that. Don't inflate statistics. Open source communities fact-check, and getting caught in exaggeration is devastating.

Competitor disparagement. Even if you think your project is better than alternatives, trashing other projects in email makes you look petty. Focus on your own value.

Surveillance-heavy tracking. If your community update email has 47 tracking pixels, you're treating community members as marketing targets. That's philosophically incompatible with open source values. Track what you need for deliverability and nothing more.

Building Your Open Source Email Program

If you're starting from scratch, here's a reasonable progression:

Phase 1: Essential communication. Set up release announcements and security advisories first. These are non-negotiable—your users need to know about new versions and security issues.

Phase 2: Community building. Add a community newsletter/update once you have enough happening to share regularly. Focus on making people feel connected to the project.

Phase 3: Contributor recognition. As your contributor base grows, add systematic recognition and contributor-specific communication.

Phase 4: Commercial layer (if applicable). Only if you have a commercial offering, and completely separate from community lists, add opt-in commercial communication.

For each phase, think about:

Who is this email for? (User type, not marketing segment)
What value does it provide them? (Not you—them)
Would a respected community member be proud to send this?

That last question is a good filter. Before every email, ask: would a trusted maintainer send this? If the answer is no, don't send it.

Measuring Success in Open Source Email

Open source email metrics should focus on community health, not conversion rates.

Healthy community indicators:

Community list growth that matches project adoption
Low unsubscribe rates on community communication
Replies to emails asking for input
Uptick in contribution activity following contributor recognition
Attendance at events announced via email
Discussion in linked forums after sending

Warning signs:

Unsubscribes spike after specific email types
Community email engagement drops while commercial email engagement stays stable (this suggests list contamination)
People complain about email frequency or content in forums
Contributors mention feeling "marketed to"

If you're running commercial email alongside community email, track them completely separately. The metrics that matter for each are different, and combining them obscures problems in both.

The Philosophy Behind It All

Open source email isn't about conversion funnels or engagement metrics. It's about maintaining the trust that makes open source communities possible.

Every email you send either strengthens or weakens the relationship between your project and its community. There's no neutral. The community update that provides genuine value strengthens connection. The update that's padded with fluff weakens it, just a little. Those "just a little" moments add up.

The companies that successfully build businesses around open source understand this intuitively. They treat community communication as sacred—separate from commercial goals, focused entirely on community value. And paradoxically, this separation is exactly what makes their commercial offerings successful. When people trust your open source communication, they're more likely to trust your commercial offerings when they're actually relevant.

If you're building an open source project and wondering how email fits in, start with one question: what would genuinely help my community? Answer that honestly, and the email strategy follows naturally. Try to optimize for your own goals at the expense of community trust, and you'll eventually have neither the community nor the goals.

For guidance on building product update communications that respect your audience, see our product updates newsletter guide.