You can adjust how emails to be shown in Webmail:

1) Without preview

2) With message previews

To change the Message previews setting:

1. Select the app selector (top left of Webmail).
2. Select Settings
   
   
   
    
3. Select Mail
   
   
   
    
4. Toggle the Message previews - Toggle to enable/disable the message previews in your email list to suit your preference