Every website on the net has the mailing functionalty, due to the access use of the mailing functioanlty lots of hosting provider or service provdeer keep the cap on the sending mail from the PHP mail function and most of he time the PHP mail function do not work properly.

koolphp provide the SMTP mailing solution to the system. The confgiuration of the SMTP is done in the config.inc.php you can check out more details from INSTALLATION > CONFIGURATION