You can stop unwated email by applying email filters, you need to login to your cPanel control panel to do this.
You can filter email either using the "User Level Filtering" which allows different rules for each email address you have setup or "Account Level Filtering" which will affect all email accounts you have setup.
You can create rules to filter based on the following:
- Sender (from)
- To (destination email address)
- Message Header
- Message Body
Please be careful when using this feature to make sure you don't block legitimate or all your email by mistake. Also, please do not use special characters (hash, star, hyphen, etc, etc) in the blocking rules as these are likely to break your email.