We were having an issue where spams emails were sent from single cpanel account
We could not suspend the account and disable emails
So the solution to this was to keep website online and disable only emails
we use the below method to disable emails for a single cPanel account.
SSH to server and use below steps to disable cpanel for any account
The newwebho is the cpanel user name
root@online [~]# chmod 0 /home/newwebho/etc/
root@online[~]# chattr +ia /home/newwebho/etc/