Deleting emails from the default cPanel Account Email Address
Warning! Advanced users only.
If the default cPanel email address has filled up with unwanted or junk emails and you would like to delete them all in one go, this is possible to do via FTP. It is important, however, that you only delete the correct directory outlined in this post.
The directory which is to be removed is /mail/cur, or if you are doing this from shell access on your dedicated server, /usr/home/username/mail/cur where username is the account username in question. There should be three directories present - cur, new and tmp. These directories will be created automatically when new mail arrives.
If you are in any way unsure, raise a support ticket and we can handle this for you. Alternatively if there are not a huge amount of emails you may attempt to download them.