Sorting Mails on SquirrelMail Web Interface.
1. Ensure 'Always Show Full Date' is checked. To do this go to Options, under Display Preferences look for 'Always Show Full Date' and check it.
2. In the inbox area, check that it shows “Thread View” as a link. If it instead has “Unthread View”, Simply click “Unthread view” link to switch it back to threaded
3. Sort Messages using Received/Date checkbox and messages will be sorted and new messages will be displayed on top of the inbox area.