I Have owned a web hosting company.Will all my customers have their own H-sphere/webmail login

Yes, your customers can have own H-sphere login, and you can set up their email accounts from your master account.

thanks Dolbz

how can i create new email account?

Simply log in to your account and open the “Settings” menu, then click on “Email Accounts”. From here you can select “Add User” to create a new email account.