It has been a long time coming. I used to work on a similar concept in a CRM startup about ten years ago. The project turned out quite bad because I did know about email protocols but not much about email providers and interoperability issues, so the project was later scrapped and replaced with an external service.

After many years I saw that the problem still exists - it is hard to integrate services with customers' mailboxes unless it's something straightforward like triggering a Zap for an incoming email. So, equipped with all the experience I'd gained during these years, I decided to tackle that issue again, this time under my own company.

I have made no targeted sales, and I never was in touch with the first paying customers. The only companies I discussed EmailEngine on my initiative are running it for free to this day, so these don't count as customers.

EmailEngine was first a free open source project, it gained quite a following on Github, and once I started charging for it, some of the users converted to have a paid subscription to get the upgrades.

I've done a lot of open source work over the years. For example, my most known project, Nodemailer, is the default library in the Node.js ecosystem to send emails. It has around 15 thousand stars on Github and is used by many companies worldwide, both small and large. So all those developers, who are building something around email with Node.js, come to Nodemailer's homepage for documentation and examples. Nodemailer's homepage, where I feature EmailEngine, has been by far the primary driver of sending traffic to EmailEngine's homepage.

I also get some organic search traffic for topics around OAuth2 with Gmail / Outlook. EmailEngine is also listed in DigitalOcean's 1-click app Marketplace, and I've got some customers from there as well.

The classic, if you do not start, you will never get anywhere.