users generally can…
User must be aware whether his/her mailbox is at Kerio mailserver or Zimbra mailserver
CERGE-EI Webmail - Kerio https://mbox.cerge-ei.cz/
(login with your username)
CERGE-EI Webmail Zimbra https://mail.cerge-ei.cz/
(login with your username)
Kerio Mailserver
Zimba Mailserver
You can check occupied mailbox space by pointing the mouse pointer at the line under your mailbox name (in top right corner)
You can check size of each folder by pointing mouse pointer at the respective folder name
You can check occupied mailbox space and your quota if you click at the mailbox name (in the left pane)