Fun facts, I own a domain name and created a new email address.

I’m currently considering making it my main email address.

Also a good reason so leave outlook and gmail.

Note that if you let your domain lapse and someone else registers it afterwards, that person will also gain control over your e-mail address.

Wow, are you serious? That’s crazy!

What if I delete everything if I ever let my domain lapse?

In the same time, it is the name of my company, I assume I will keep it forever until I die.

As long as you’re very thorough about removing any link from your expired e-mail, you should be OK. That includes all accounts that you registered using this e-mail, as well as all e-mail contacts that you’ve built up using that account.