I will guide you how to create a mail account via SSH. Basically, you can create email account via cPanel with a friendly UI but creating an email account in SSH is completed faster and simpler.
To create email account from SSH, you need to have root account and using CD command to reach out to Scripts directory.
When you are moved to script folder, you type ./addpop
At this step, it will ask you for email account name and password.
If you just enter your personal information and press "Enter", your mail account will be created.