Email verification is a method to confirm that a subscriber has provided a correct email and actually wishes to receive important updates from your company. When a visitor subscribes to an organization's email list, they receive a unique link in their provided email's inbox to approve receiving emails from said business.
This link both protects the business from having unvalidated email adresses and the user from getting unwanted emails. Email verification also helps in the improvement of a company's email account.
Reaching the right customers is crucial for businesses in order to not end up in subscribers' spam folders.
There are many verification tools that are freely available online. Using those tools eases things for organizations who wish to undergo email list cleaning.