Since 2014, ICANN, the top-level organization that manages all domains worldwide, has a policy that the email address associated with a domain name must be verified.
This is why we send an email with a verification link to the Registrant (owner) email address for all domains registered through our company.
If you do not click on the link in any of the four emails that we send over a period of 15 days, all domains that use this email address get suspended.
As the verification is per email address, not per domain, once your email address is verified, you will be able to use it for other domains in the future without further verification.