To create a new email account, just login into your mail account as under:
Like if your domain name is "www.webexperts.com" you will have to login with http://webexperts.com:8383
Then put the user name & password which you received in your welcome mail while you took the hosting plan.
After putting your user name & password to the above window, the new window will open as under:
Click on User Administration
And After clicking on user administration now you can add a new mail account shown as under:
Now Put the required information and also check the services which you want to give to your email user