Have you received the infamous "Disk Usage Warning" email message?
If you are running out of space for your website, you may upgrade to a higher capacity plan. Log into your client area and choose the hosting account in question and click 'upgrade account'.
If you do not wish to upgrade you may be able to reclaim some space by deleting files from your account.
1. All of your log files are stored in the /tmp directory and organized by name of the particular program used to create the files. You may delete unwanted or old access log files at your convenience.
2. Although there may be no user email accounts, a default email account is created for all domains for error reporting. The main account name has an email account and there may be lots of mail with contents. Log into that default email account and delete the emails. Or it may be easier/faster to traverse the directory structure and remove the unwanted files from the /mail directory. Pay particular attention to the /main/cur directory.
3. Set the default address for your main user account to "FAIL". Click on "Default Address" from your account control panel.