We all have different ways of managing our inboxes -- or trying to. Despite the countless hacks, tips and suggestions on email productivity, inbox zero often remains illusive.

Even de-cluttering guru Marie Kondo has advice. Some strategies are extreme, like Barbara Corcoran's decision to stop replying entirely and send this auto-reply instead.

Her Shark Tank co-star Mark Cuban takes a far different approach. He does everything the productivity gurus say you shouldn't do: He checks his email constantly.

Cuban says he uses every spare moment to stay on top of his inbox. He does as much business as he can via email, which allows him to avoid time-sucking meetings and phone calls. "No meetings or phone calls unless I'm picking up a check. Everything is email," he said on the Thrive Global podcast.

Cuban is not only the owner of the Dallas Mavericks, but also has part ownership in dozens of companies. One can imagine that his inbox is several hundred or thousands of emails deep. Yet according to one of his Shark Tank companies, Guardian Kids Bikes, Cuban is still extremely accessible and responsive. Here's how he manages his inbox and makes the most out of every email.

Give people direction

An effective email strategy means you need to manage what comes in. If you can set a few expectations and mutually-agreed upon rules with people you frequently email with, you'll already be in more control of your inbox. This keeps the lines of communication open -- but with a few parameters that everyone is aware of.

Cuban asks that all his Shark Tank companies send him a weekly digest email, Guardian Kids Bikes wrote in a blog post. "We email Mark [personally] every week. He wants a weekly update from us to know what's going on and to stay involved."

With this system in place, Cuban always knows that he will hear from his companies at least once a week. He doesn't need to check in on them. He's always in the loop. "If he can get email updates from us every week and have a pattern of our condition and what's going on, it enables him to give really great advice," says Guardian Kids Bikes co-founder and CEO Brian Riley.

Keep your response as brief as possible

Riley says Cuban always keeps his responses brief. "He usually gets his point across in a sentence, sometimes a few words," Riley explains. "I think the most he's ever written us was probably like three or four sentences."

Long-winded emails are not just time-consuming to write. They're somewhat inconsiderate to the person who receives them, because they also take a long time to read.

Challenge yourself to write shorter emails. After you finish drafting an email, stop before you hit send. See if you can shave 20-30 percent of the text. You probably can. Do this every time, and your emails will naturally start getting shorter. You're more likely to receive a reply if you keep it short, especially if it's a cold email. And don't forget to end with a pleasant sign-off to increase your response rate.

Start with the bad news

Another way Cuban gets to the point is by ignoring pleasantries entirely. And he encourages the employees and entrepreneurs who email him to do the same. Cuban doesn't want the song and dance. He wants to get the to heart of the matter so he can move into problem-solving mode.

Here's what Cuban said on an episode of Thrive Global:

"I assume you're going to do well. That's why I invested in you. I assume you're hiring amazing people. That's why you hire them. But where I can add value is by dealing with the problems. And so hit me with the bad news first. Let me try to help you in any way I can and then let me move on to the next one."

Put Cuban's email strategies to the test and see if your inbox load starts feeling lighter. And remember, you don't have to respond to everything. Nor do you have to apologize if it takes you a few days to reply.