Should have asked that in the "coding inside your component" section...
Send a mail on saving a form ?
Then you have to implement it in the controller, in the function save()
$mailer =& JFactory::getMailer();
$config =& JFactory::getConfig();
$sender = array(
$config->getValue( 'config.mailfrom' ),
$config->getValue( 'config.fromname' ));
$mailer->setSender($sender);
$mailer->Encoding = 'base64';
$body = "blabla <br />";
$body .= "blabla <span style = 'font-weight:bold; color:red;'>\"" . $variable . "\"</span><br />
$mailer->setSubject('Your Subject');
$mailer->setBody($body);
$send =& $mailer->Send();
if ( $send !== true ) {
echo 'Error sending email: ' . $send->message;
} else {
$app = JFactory::getApplication();
$app->enqueueMessage('Mail Sent');
}