E-mails can be deleted from the client area or the control panel.
Deleting e-mails in the control panel
Once you have logged in to your control panel scroll down to E-mail Manager and click on E-mail Accounts.
Check on the e-mail to delete.
Click on Delete.
Deleting e-mails in the client area
Log in to your client area
Click on My Services.
Click on the active link of the domain to delete e-mails.
Then scroll down to Email Management and click on email accounts.
Check the e-mail to delete and then click on the delete button.