NEW ICANN RULES REQUIRE VERIFIED EMAIL ADDRESSES ON ALL DOMAINS
Due to new ICANN policies that started January 1, 2014, it is now imperative that the Registrant/Owner email address listed on your Whois record is correct. Failure to complete verification requests sent to the domain owner email address will result in domain suspension.

This new policy affects all domains on the internet, not just the ones registered through DomainRocket.  To learn a little more about the background of this policy, read the following news article:

A big website is going to go dark thanks to ICANN’s new Whois verification

A verification request will be sent for any new registration, transfer in, contact updates (First name, last name or email address), or when mandatory email reminders (including Whois data verification requests, domain renewal reminders) bounce back.  Once the verification request has begun, the Owner/Registrant email address must be validated within 15 days, or the domain will be suspended.  During this time, multiple emails will be sent (including one to the billing and technical contacts on the domain(s), as follows:

See also:

Registrant Validation FAQ

How can I know if my domain was suspended because of the ICANN contact verification policies?

Recovering a Suspended Domain