In order to access Webmail, you will need to go to:
On the Webmail login page you need to enter the email address you wish to access and the password for the email account. The password is the one you chose when you created the Email Account in cPanel.
Forgot Email Account Password
If you’ve forgotten your email account password you can reset it inside your cPanel by clicking the Email Accounts icon.
Then click the Manage button beside the Email Account and on the following page you will be able to reset your password.