[imp] Maximum execution time exceeded problem

[Paul.LKW]

Dear all
    As I make a large attachment to IMP for sending out, I get the =
following error:
        Fatal error: Maximum execution time of 30 seconds exceeded in =
/home/WWW/mfun.org/html/horde/imp/compose.php on line 908
 I have already set the Resource Limits in the php.ini file as the =
following:
        max_execution_time =3D 600
        max_input_time =3D 600
        memory_limit =3D 16M
and the Apache /etc/httpd/conf/httpd.conf file's=20
        Timeout =3D 600
what can I fix it ? Thanks for your kindly reply and help.