Email disk space

To see the current disk usage for all your POP accounts, log in to the SmarterMail interface as the 'Postmaster' account.

To log in as Postmaster, go to the Email Management page in the Site Info Manager section of Control Panel.
 
Click the "SmarterMail Manager" text and you'll be taken to the SmarterMail interface. Once logged in to webmail, go to Domain Reports > Disk Usage. There you can see all users, their disk usage, their disk space limit, and totals.

Note: SmarterMail doesn't query the physical disk, the Totals will show the sum of the users quotas. Therefore it's possible that Totals can show a limit greater than your actual disk limit. The "Disk Usage" window from the "Overview" report will show the overall total allowed for your domain.  It will say "# KB of ###.0 MB space free".  The second number is your disk space limit for all the accounts in your domain.

If you've reached your Email Disk Space limit, you can upgrade your Winhost plan or remove emails to free disk space up. See this KB article to upgrade your Winhost plan. If you have deleted email, you may need to remove it from the recycle bin to free the disk space.