About us
Your email is run by someone who has sat on your side of the table
One Mail Studio was not born out of a Klaviyo course, but out of having been in the founder’s chair: with a P&L, a cash balance to hit and the pressure of every euro invested having to come back.
Our story
How it all began
I co-founded Hemper, an e-commerce brand with which we sold more than a million euros in Spain, almost all of it through Meta. It worked so well that I never asked myself the important question. Every euro came back multiplied by five, by six, some months by ten. So we poured in more and more, and we built the team and the structure on top of that.
Until the market matured, costs went up and ROAS dropped below six. In a matter of weeks, a business that seemed solid was left hanging on a channel that no longer delivered, and that had never fully been ours.
That is where the agency’s thesis came from: your most profitable channel is the only one that is truly yours. You control your email list and no algorithm can take it away. I built One Mail Studio to help founders like you build it right, before learning the lesson the hard way.
We’d built on rented land.
Manuel Sierra
Co-founder of One Mail Studio
One Mail Studio results to date
+€1.1M
in sales attributed to email
+21,000
orders generated
~42%
average open rate
+13.5M
emails sent
Our values
Built with judgment
A channel of your own is worth more than a rented one
Meta and Google rent attention; your email list is a brand asset forever. That is where we put our focus.
Specialization wins
Email only, and only for e-commerce on Klaviyo and Shopify. Doing one thing thoroughly makes us better than any generalist.
Depth over volume
Few accounts, worked on for real. We study your brand before touching anything and leave the month built with a buffer.
Partners, not vendors
We step into your business as part of your team, with our own judgment and skin in the game to make the results happen.
Ready for your email marketing to deliver real results?
Book a free audit and we’ll show you the real potential of your email channel.