These emails are sent to confirm the WHOIS information you have provided is correct.  This is a policy of ICANN (https://www.icann.org/get-started).

To review/update the WHOIS information, you will need to login to your client area via http://www.letshostbilling.com/clientarea.php and click on Domains > My Domains > Active (beside the domain) > Manage : Contact Information.

If you receive such an email, please confirm ownership of the domain but if you suspect this may be a phishing email or similar, please do not hesitate to contact our support teams.

If the WHOIS information is correct and up to date, you just need to click on the link provided in the mail to confirm.  If not, you need to make the necessary changes, another email will then be sent requesting you to verify the information is correct.