We are using Salesforce REST OAuth API for creating events. Here is the sample -

$content =json_encode(array("ActivityDateTime"=>$start,"WhoId"=>$userid,"Subject"=>$name,"StartDateTime"=>$start,"DurationInMinutes"=>30));
$obj=new sfdc_API($access_token,$instance_url);
$action="sobjects/Event/";
$contactURL=$obj->apiURL($action);
$obj->httpPost($contactURL,$content); // PHP Curl Post Request   

This code is creating an Event on Salesforce for the Contact ( Mentioned in WhoId) but its not sending the email. We want to send an email as well by Salesforce only.

Thanks in advance.