In order to create email accounts in cPanel, follow the steps below:
Email quota is used from the available disk space in your hosting account, if you don't set a limit it will also email address to use up to the entire available disk space of your account. In the event your disk space is full, received emails will not be delivered and may bounce if disk space is not cleared or increased.
Once the email account setup is complete, email owners can directly login to webmail from the link yourdomain.com/webmail.