ICANN - the governing body for all domain names - has requested that Registrars (2MHost) verify the Registrant (domain owner) email address associated with new domain name registrations. So, after a new domain registration, or after you change the first name, last name or email address associated with your domain name, you will receive a message at your domain registrant new email address, If you click on the link in that message within 15 calendar days, registrar will accept your new contact information as verified. and the Registrant (domain owner) is then considered verified and will require no further verification.
Once a Registrant contact has completed the verification process, all future domain names that are updated or registered to this same contact information will not be subject to the verification process.
If you missed the verification message, the registrar will suspend your domain name and put it under status: clienthold
To fix the problem, first you may try to find the verification message and verify/approve your contact information, you can find the email address of the verification by checking your admin area > domains > Your domains > click on the domain name to launch the domain name manager > choose 'Contact information' from the side menu, the email address is the registrant email address
then, go to this mail box, find out the verification message (check the spam/junk box too) and click on the verification link in it.
if this address is no longer valid, then put your current address and click "save contact information", after that, go to the new mail box, find out the verification email and verify it.
the domain will be up immediatly, but due DNS cache, it may take few hours for the domain to be viewable globally