I wasn't planning on hosting this stupid page on this domain if it weren't for some people being stupid. This is my domain, I own it, the only purpose is for email filtering.
I basically give out specific emails for each service, for instance: facebook gets [email protected], github gets [email protected]. If your company's name is company-name, you've probably received [email protected]

You're most likely wrong. The email I gave you which ends on cyberhck.dev IS valid.

Explanation: There are good questions and there are other type of question. This isn't a good question.
If I've given you the email, the way you can verify if the email is invalid is by just sending the email. If your service sends verification emails, then doesn't that already filter out non-existing emails? Why are you in this stupid website? If you still think this email is invalid, either you're wrong, or I am. But I can definitely assure you that I'm using these E-Mails for a while now.
You still think email is invalid? Check the screenshots on those links, I've linked to screenshot of my accounts on various platforms I no longer care about.

Frankly, weather or not this is complicated is none of your business, your system needs an email so that it can send me information, use it.
For the other part of question, I'm doing this because I don't trust your systems. When your system gets compromised, or you sell my information to 3rd party companies, I'll be able to notice I'm getting spam emails on the email I gave to you, after which I can do two things:

• delete the mailbox so that email isn't valid anymore and then update the email address on the system.
• do something with the knowledge that my email which was provided to you was leaked.

Find your way to haveibeenpawned and see if your information have ever been compromised. In my case I've been exposed and here are the details:

• 000webhost exposed my emails, IP addresses, my name and my password in PLAIN TEXT!!! (WTF!)
• I signed up for 500px for some reason, and they exposed my email address, name, username, gender, date of birth, and hash of my password
• Time for a big company, adobe exposed my email address, username and encrypted password (not hashed) AND password hint. Encryption was poor and quickly was broken! fuckin' adobe!!
• Gravatar exposed my name, username, and md5 hash of my email, not too bad, but come on!
• LinkedIn exposed my email address as well as unsalted hash of my password! LinkedIn!, seriously, I'm not even kidding, LinkedIn!
• TRAI (Telecom Regulatory Authority of India) exposed my email address as well as the body of email which I sent them when I was studying back in India.

After seeing this stupidity from even big companies, I've decided to change the way I approach security. Instead of worrying about my email address being exposed, I'm assuming that it'll get leaked at some point. There's nothing I can do about it. (Which is also why I favor 1Password over any other password managers).

What I can do however is give every system separate mailbox, every single mailbox forwards incoming emails into my personal inbox. And WHEN a system is compromised, I simply delete that mailbox (if I find out that way), however even if a company tries to hide it, the minute I get an email not from them, but from someone else (weather the company made a mistake, or they willingly sold the data to someone else), I immediately know I'm exposed, all I have to do is simply delete the mailbox.

You have multiple ways of doing this, all of them with varying degree of complexity. In any of those, you'll need a domain name. I purchase mine from google domains, I'm sure you can do it from somewhere else.
Once you have your domain, you have the following options

• simply set up your domain to forward all your incoming mails to your primary email address.
  The downside of this is anyone can send you email targeting any email address, like [email protected] would still land in your primary email address, you can get by with this method as long as there's no one targeting you.
  The upside however is very easy
• create individual email address and have them forward to your primary address
  While this takes some time for individual addresses, it protects you from the first scenario.
• Create a filter in your primary email account where incoming email sent to a email which isn't in "known-emails" is marked as spam create individual email using terraform and have some random suffix at the end, that way no one can really guess email either. OR you can even think it yourself and sign up first, and later go to your primary email and add it to known-emails list on your filter, and it'll stop sending that email to spam.