The co-founder teaching your inbox to write back - in 18 languages, before you have your coffee.
Open Outlook on a Monday and there it is: forty unread threads, three of which start with "per my last email." Adrian Cabrera de Luis decided that the worst email is the one you have to write yourself. So he built a company to write it for you.
Today he is co-founder and CEO of Maestro Labs, the team behind MailMaestro, TeamsMaestro and CalMaestro - a small suite of AI assistants that draft replies, summarize threads, take meeting notes and wrangle your calendar, all without leaving the inbox you already live in. It runs inside Outlook and Gmail, it answers in eighteen languages, and in head-to-head testing eight of ten people picked it over Microsoft's own Copilot.
That last detail is the whole pitch. A 14-person company, headquartered in Singapore, run by a CEO in New York, out-charming the assistant that ships inside the world's biggest email client. Not by being bigger. By being better at the one boring thing everyone hates.
"We're taking a major leap forward in our mission to transform email productivity with AI globally."Adrian Cabrera de Luis · on acquiring Flowrite, Jan 2025
He studied microengineering at EPFL in Switzerland - the science of building things at the millimeter scale. Precision before product. Long before he thought about software, he thought about tolerances.
Boston Consulting Group. The classic crucible where smart people learn to turn a mess into a slide. He learned how big organizations actually decide things - and how slowly.
An MBA at MIT Sloan, concentrating in entrepreneurship. He has called the MIT crowd refreshingly honest - founders comparing scars instead of pretending everything works.
Alpaca started as an apartment-rental site in Germany that couldn't afford its own ads. So they grew on Facebook groups instead - and reached more than 2 million members, adding 120,000 a month.
Alpaca was acquired by Boom, where he stayed on as Head of Growth. One company built, one company sold, before most founders finish picking a logo.
He co-founds Maestro Labs and ships MailMaestro - an AI email assistant for Outlook that quietly climbs to the top of Microsoft AppSource.
In blind, head-to-head testing of email drafts, eight out of ten users preferred MailMaestro over Microsoft Copilot for Outlook. When you build inside someone else's product and still beat their version, you have made your point about focus.
User preference - MailMaestro vs Microsoft Copilot for Outlook
Source: Maestro Labs / Flowrite acquisition announcement, 2025
In January 2025 Maestro Labs acquired Flowrite, the email division of Helsinki's Flow AI. Flowrite had reached hundreds of thousands of users across 150-plus countries and raised around 5 million dollars. The prize wasn't just users - it was Gmail. MailMaestro had owned Outlook; Flowrite opened the other half of the world's inboxes.
It is a tidy bit of strategy from a man who once grew a startup on Facebook groups because ads were too expensive. When the cheapest path to a market is buying the company already standing in it, you buy the company. The seed round behind the move drew checks from family offices and senior executives at Microsoft, BCG, SoftBank and KKR.
MailMaestro - drafts, improves and summarizes email in Outlook & Gmail.
TeamsMaestro - AI note-taker for Microsoft Teams, transcribing meetings in 20+ languages.
CalMaestro - turns the calendar into something that schedules itself.
"We've always admired Flowrite's innovative approach and rapid growth - reaching hundreds of thousands of users across 150+ countries in a very short period is an impressive feat."
On the Flowrite acquisition, 2025"There will be lots of signals around why you should stop, or why you should give up."
On building Alpaca, MIT InnovatorsAlpaca began as a rental website that couldn't afford Google and Facebook ads. The pivot to free Facebook communities was a survival move that turned into millions of members.
He ran Alpaca with co-founders in Germany and Chile while sitting in a classroom at MIT in Boston. The hardest feature to ship was a shared calendar that actually worked.
Bolivian, Spanish and Swiss heritage, schooled in Lausanne and Cambridge, now in New York running a company headquartered in Singapore. The 18-language product makes more sense once you know the founder.
Before growth decks and AI prompts, he trained as a microengineer - a field obsessed with getting tiny things exactly right. It shows in a product judged on the quality of a single sentence.
Roughly 14 people stand behind a product used by tens of thousands of teams in 150+ countries. Leverage, not headcount.
Two companies, both built on the same instinct: find the expensive, annoying thing everyone tolerates, then make it cheap and quiet. First it was finding an apartment. Now it's answering your mail.