My clients is having problem accessing the webmail. I've check the scripalias directive and it seems to perfect. I doubt its an apache problem as I'm accessing it through port 2096. here's the cpanel error_log
i tried upcp --force, fixeverything, restart cpanel. none works for me 
Code:
Content-type: text/html
Internal Error: "GET /3rdparty/squirrelmail/index.php HTTP/1.1" Unable to open engine binary (php) at cpsrvd.pl line 4482
main::phpHandler() called at cpsrvd.pl line 3383
main::dodoc_webmaild() called at cpsrvd.pl line 635
main::dodoc() called at cpsrvd.pl line 541