EmailEngine made €750 in 18 months. Then it made $2,000 in one.

Andris Reinman registered a company in 2020. In the first year and a half, it found three paying customers. Each paid €250.

That is €750 in about 18 months.

Then he changed how the product was sold. The first month under the new model brought in $2,000. That was "more than twice what I had made during the previous year and a half combined," he wrote on the EmailEngine blog on 2 November.

The price had not moved. It was still €250 a year. And the software, in his words, "was largely the same."

Today EmailEngine makes $20k in monthly recurring revenue (MRR). Reinman runs it alone. No employees, no investors, no sales team.

What he was selling

EmailEngine is a REST API that sits on top of IMAP, the protocol mail servers use to hand out email. You connect mailboxes to it, and your app talks to the API instead of the mail server.

It started out as "IMAP API", one item in a small portfolio. Reinman's plan was to release email tools under the AGPL, a restrictive open-source licence. Paying subscribers could use the same code under the MIT licence, which companies find easier to live with.

So the product was free. What cost money was a different licence for the same code.

It barely sold. He doubts even the three buyers were real customers: "It seemed they mostly wanted to support my work rather than actually needing a commercial license."

His diagnosis is the line worth keeping:

"I was trying to sell a solution to a licensing problem that most of my potential customers did not actually have."

Big companies were not going to adopt unknown software because it came with an AGPL escape hatch. Small companies rarely thought about licences at all. They wanted something that worked.

The free takeaway: if your paid tier fixes a problem only lawyers have, most buyers will not pay for it. Charge for the thing they already use.

The switch

Reinman made three changes at once.

1. He renamed IMAP API to EmailEngine. The old GitHub repo, andris9/imapapi, now redirects to postalsys/emailengine.
2. He built a user interface.
3. He made a paid licence key required. "Without a valid license key, the software would stop operating."

The licence itself went from AGPL to a commercial one. The code stayed public on GitHub, so EmailEngine became source-available: you can read it, but you pay to run it. The repo's README says so today, with one softener. Each instance gets a free 14-day trial.

The old AGPL package is still on npm. Its last release, version 1.8.2, went out on 25 July 2021.

All of that first $2,000 came from companies already running the free IMAP API. They wanted to keep using it and keep getting updates. Asked to pay for something they relied on, they paid.

"I had not suddenly built a much better product or discovered some revolutionary marketing strategy," he wrote. "I had just changed how I charged for it."

The clause that made it possible

Most founders skip past this part. It matters most.

You cannot relicense code you do not own. If outside contributors had kept the rights to their code under the AGPL, Reinman could not have moved the whole project to a commercial licence.

He could, because of a decision made at the start. He "had required outside contributors to sign a Contributor License Agreement (CLA) from the beginning." A CLA is a contract where each contributor grants the project's owner rights over what they submit.

The switch that turned €750 into a business depended on paperwork he required from the very first outside contribution, long before the project earned real money. If you run an open-source project you might one day charge for, that is the cheapest decision in this story to copy.

Focus, then price

Once the new model worked, he stopped selling the other projects. He made them free and put all his effort into EmailEngine.

That matched what the market had already told him. The other libraries "got almost no attention" on GitHub. IMAP API got users and stars. The EmailEngine repo has 2,248 stars today.

Then he raised prices, slowly, over several years. The Postal Systems plans page lists the subscription today at €1,200 a year, or $1,450 in US dollars. That covers unlimited instances and unlimited IMAP accounts.

In euros, that is 4.8 times the old €250.

"Increasing prices did not seem to reduce the number of new customers," he wrote. For a business that needs the software, "the difference was not particularly important. The software either solved a problem worth paying for or it didn't."

Here is some arithmetic of our own. $20k a month is $240k a year. At $1,450 a year each, that would be about 165 subscriptions. Reinman gives no customer count, and the plans page also offers custom terms and perpetual licences. So treat 165 as a rough scale, not a number he gave.

The long part

The headline numbers hide the timeline. Reinman is blunt about it.

• 2011: he starts Nodemailer, the Node.js email library. Back then, one of the better ways to send email from Node was to pipe it to a PHP script.
• June 2013: he hears Mike Perham on The Changelog, episode #92. Perham sold licences for commercial features of Sidekiq, his otherwise free job-queue library. "I was hooked from the start."
• The next seven years: open-source projects with paid parts, SaaS experiments. "My success rate was exactly zero."
• 2020: COVID lockdowns. He registers the company, opens a bank account, signs up for Stripe. "There was just one small problem. I still had nothing to charge for."
• About 18 months later: €750 total, and the switch.
• Now: $20k MRR.

Would he tell someone who just lost their job to do this? "Not necessarily." He credits years of open-source work for "experience, credibility, and an audience in a very specific niche," and says there was "a lot of luck involved."

So the reusable part is not the speed. It is the order: own your code from day one, find the project people actually run, then charge for running it, not for a licence they never needed.