I didn't really plan to write about Zero at all - it didn't seem like much of anything to me. Until I learned that they had raised 2 million dollars and wanted me to chat with them.
They quickly rescinded that offer to talk, but I still have a lot of thoughts. So let's dive into what Mail0 is, and what it should be.
(Oh, and Nizzy, if you change your mind, I'm still down to chat. No hard feeliungs to you or the team.)
What even is mail0?
Zero is, effectively AI + email. Far from a new innovation, but they want to do it so well that they replace Gmail. Zero allows you to chat with your inbox, summarise conversations and compose replies, all in a smooth, clean and open source interface.
They started as an indie hacker project, that quickly gained steam on X before being backed by Vercel and later on, picked up by Y Combinator as part of the Spring 2025 batch.
They market INCREDIBLY well. They have the foundation. They have the attention. However, when you want to build an idea that you aren't the first to, you either need to be the best at selling it, or the best at executing it.
I feel like in it's current state, Zero does neither.
The pain points.
Zero relies on Gmail only for it's email connections, placing it in a very volatile position where Google could essentially send their platform under with a click of a button. It also creates a lot of frustration among customers who use other email providers, and limits your audience.
Next, let's talk about the AI features. Your AI feels loud, pronounced. Everyone either already has this, or will have it in the next twelve months. The last thing you want is to end up overshadowed by the tools you use as a backbone.
My suggestion is get the fundamentals right to an art so that your client feels wonderful to use. Profile pictures even if they aren't sent in the email. Intelligent sorting and grouping of mail. Smarter search. One click intuitive cleanups. Build things fix what frustrates you with email first, then your tool has soul. People will want to use your tool not just because it has AI or rides a trend - but because it's a genuinely good tool that elicits positive rapport from consumers.
Next, the AI. I think it should exist, but not as a chatbot. Rather than making me type a message to find my flight reference, why not compile the info from my travel emails into one defined space, where I can copy info with just a click? What if it could have a card showing my packages, automatically? The real time savers will come from agents that understand, not ones we instruct.
Lastly. I want to briefly touch on business model since you've got investors now. Getting people to pay for an email client is HARD. I have an email client that I swear by but still hesitate to pay for, simply because it's something people have taken for granted. If you want people to cross that line and pay for yours, you're going to really have to show them how it can revolutionise their mailbox, or lure with exclusivity.
In summary.
Zero is striving to fill an undeniable gap in the market - and I strongly commend them for it. I think they really just need to get a focus on either what's going to set them apart, or how they're going to surpass everyone else in UX to be the best, even while relying on companies that strive to beat them.