Path to sendmail
/usr/sbin/sendmail
Here is a SIMPLE TEST PHP Sendmail Script:
<?php
$to = "To@yourdomain.com";
$subject = "This is a test";
$message = "Hi! This is a test .";
$from = "From@yourdomain.com ";
$headers = "From:" . $from;
mail($to,$subject,$message,$headers);
echo "Mail Sent.";
?>
Here is our Shared Hosting PHP Spec Sheet: