If you want to have an email account inaccessible without deleting it, you can suspend it and later on unsuspend the account. Learn how to suspend and unsuspend email account through the cPanel by following the instructions below.
Step 1. Log in to the cPanel.
Step 2. Under Email panel click on Email Accounts.
Step 3. Email Accounts tab, look for the email address you want to suspend.
Step 4. Click Manage Suspension and tick “Suspend” of any of the following and "Click Save".
Login – this only allows incoming emails but blocks login to email account or sending out emails
Receive – blocks receiving emails but allow sending out emails
Send – blocks sending out emails but allow receiving emails
Unsuspend Email Account
If you wish to reverse the process and make the email account work again, use the same steps and select the “Allow” option and click on "Save" button.