Mail Calendar

Hi you all.
Can someone tell me something about this line that I get everytime I try to set event on webmail calendar?

Warning: fopen(/var/spool/squirrelmail/ failed to open stream: Permission denied in /usr/local/ndn/web/squirrelmail-1.4.2/plugins/calendar/calendar_data.php on line 58


I’m not quite sure about the app, but that error just means that the permissions aren’t correct for /usr/local/ndn/web/squirrelmail-1.4.2/plugins/calendar/calendar_data.php (i.e. not readable by your user, or the user the webmail calendar is running as)