ICANN, the registry for all .com, .net and a few other general domain names has since January 2015 a new email validation protocol. There is an active email validation check on the email addresses that register a domain.
For this email validation, you will receive an email from ICANN with a validation link. It is important to click this validation link within 14 days. Just clicking the link in the email is enough for the validation to proceed. When you do not click the link, your domain names will be turned off and therefor your website will be down.
Tuesday, February 9, 2016