There is a compatibility issue with some versions of Internet Explorer where the body of your emails will appear blank while checking them using web-mail. There are a few ways around this problem.
While on the login screen of you Icewarp webmail, at the bottom you will see a button that says Desktop. Click on it. You will then have the option to switch to other modes. Choose Tablet mode and then log in using your username and password.
The interface will look different but you will still have all the same features as the desktop mode. You should now be able to view the body of your emails.
The other option is to download and install another web browser like Google Chrome or Mozilla Firefox. There are no compatibility issues with these web browsers.