To create the email account with your domain name please follow the below steps:
1: Open the Cpanel with the login details you have received on your registered mail.
2: Under the EMAIL section click on the option "Email accounts", in that you need to click on "Add email account" option.
3: Once you click on it you will get the options to fill email name,domain name,password once you fill all the details click on Create account.
4: Once you click on create account your domain email will be created, you can login to your webmail email with link: domainname/webmail.