His Email API Makes $130,000 Annually
How this web developer converted an open-source project into a solo startup.
Hello! Can you introduce yourself and tell us about your business?
My name is Andris Reinman. I live in Tallinn, Estonia, and I’m 42.
I’ve been in web development since the Internet Explorer 4 days.
My product is EmailEngine, a self-hosted app that exposes an API for mailbox access. Most customers are SaaS and AI companies that need to reach their users’ mailboxes without wrangling half a dozen email protocols.
EmailEngine is a tool to access emails on email servers over a simple to use REST interface. Handling native email protocols like IMAP, SMTP, and MIME directly is difficult. These protocols have evolved over many decades into very complex systems and look nothing like the HTTP protocols we are mostly used to.
How was the business started?
EmailEngine began in early 2020 as an open-source project called IMAP API.
I’d built a similar system at my previous job, and years later there still wasn’t a solid solution, so I scratched the itch myself.
The first version was tiny, just an API layer with background sync, but the core idea hasn’t changed. I soon noticed the users were almost all companies with long feature wish-lists.
Giving that away for free didn’t make sense, so after a major UI rewrite and a stack of new features I relaunched as EmailEngine, added license keys, and started charging.
From first commit to first paid invoice took about 18 months, and apart from my own time the cash spend was basically zero.
What are some of your marketing strategies?
I initially ran EmailEngine as a free open source project, mainly to gain some traction. I managed to get 3 test customers willing to pay for better license terms than the default open source one, but it took a long time.
The first revenue, about $2,000 in month one, came from companies already running the free IMAP API who wanted the new EmailEngine features.
Because plans were yearly, things quieted down right after launch, so the next months brought in just $0-$500.
To keep leads coming, I did the following:
Put up a simple homepage next to the GitHub repo and added a Mailchimp signup form.
Kept the code “source-available” so people can audit it, but require a paid license to run it.
Linked to EmailEngine from the READMEs and sites of my other projects. Nodemailer.com (the homepage for an open source email sending library I've maintained for the past 15 years) alone (~50 k visits/month) sends ~3 000 visitors to EmailEngine; even with a low conversion rate, it’s releavnt traffic.
These days, I’m focusing on mostly references from my other open-source projects plus growing organic traffic from the expanded docs on the EmailEngine site. No new channels yet.
How does the business make money?
A flat $995 per year. Early adopters keep their lower legacy price. One license covers unlimited EmailEngine instances and mailboxes; the bottleneck is the customer’s own hardware, not the license. No changes planned.
EmailEngine pulls in ~$130,000 ARR. Fixed monthly costs are about $5 k: my salary plus taxes, hosting, license-key server, accountant, and a coworking desk. The rest is profit that I take as dividends when it makes sense.
I spent around roughly 20 – 30 hours a week on the business, split between support, bug fixes, and new features.
Where can we go to learn more?