Christopher Willard/ABC via Getty Images
One of our biggest series this year is Power Hours, an inside look at the daily routines of top executives, founders, and creatives across industries. We want to understand what makes these people tick: why one wakes up at 4:15 a.m. to hydrate and meditate, another runs a 10K after arriving at the office, and a third moonlights as a Lyft driver.
When we reached out to Mark Cuban, we figured he'd be ripe for this series — a billionaire who has founded several companies, invested in hundreds of small businesses, and hosted the popular TV show "Shark Tank."
His response: "My day is boring."
"I read and respond to emails," he wrote in an email. "I work out. I read and respond to emails. I do a couple Zooms. Then I read and respond to emails. Then I eat dinner. Then I read and respond to emails." (To be fair, he also shared that he follows his morning email session with decaf coffee, a cookie, and a shower, before taking his daughter to school, then working out at LifeTime Fitness, taking a second shower — and returning to email).
This raises the question: Why is a billionaire spending most of his day in his inbox? What's so great about email? And why doesn't he hire an assistant to do all this emailing?
We had to investigate. So we sent him more emails. Here's what he told us (via email).
BI: How many emails are you reading daily?
Mark Cuban: I receive around 700 emails a day and use three phones (two Android and one iPhone) to manage everything. I'd rather get 700 to 1,000 emails than sit in long, boring meetings.
Why do you prefer emails over meetings, Slack, texts, or other communication?
I can easily search them decades later. I have emails going back to the 90s.
How do your email habits help you? Do they make you more productive? Help you avoid distractions?
It's asynchronous. I can write or respond any time, from anywhere in the world. That makes things much easier.
There's also really no limit to the type or format of the content. I can include it in emails or attach whatever.
Everyone has email. In 2025, I don't know anyone who doesn't.
It's fast. Particularly now, with Google's auto replies. For maybe 10 to 20% of my emails, I just have to choose one of Gmail's recommendations. If not, I can usually give very short responses. People expect them from me.
How do you keep your inbox organized? Do you use filters, folders, or an email extension?
I have folders. I used to have too many emails, and Gmail couldn't keep up, so I had to segregate them into different accounts. Now, that typically isn't an issue.
I spend most of my day trying to get my unreads under 20.
It acts as my tickler file and keeps what's important to me, right in front of me.
Have you ever hired someone to help manage your email? If so, how did that go? If not, have you considered it?
Never. That just slows things down.
Have you always preferred email? Or was there a moment in your career where you decided it was preferable to most other comms channels?
I started sending messages in the 1980s on CompuServe. It was fast and easy. For my company back then, I had everyone get an address. It worked great then, too.
I still have a bunch of those folders with emails!
Do you ever ignore your email (like on vacation)? Or do you always keep up with it?
For a short period of time, sure. But for a full day or longer, only in extraordinary situations like a special event for a family member.
I have a hard time disconnecting. It's faster to just get it out of the way.
Do you like to achieve Inbox Zero?
Won't ever happen. I get down under 10 now and then, but I also use my unreads as a reminder of what I need to get done today.
Would you ever consider letting AI write your emails?
Only the autoreply. Anything else, if I have a long response, I might use AI as a typing hack to save time, but I'm typically going to add some flavor somewhere.
Have colleagues, business partners, or staff ever commented on your email habits?
For a long, long time. Usually commenting that I'll respond or create emails at all hours of the day. Which is fact.
If it comes to mind, I'm writing and sending. Or if the only time I have to clean up my inbox is after everyone is in bed, that's when I'll work.
Kimanzi Constable contributed reporting.
