There are differences between "native" PHP code and PHPR code when trying to send email from within.
If you are using PHP code that worked on a php page, it might have contained this line:
Example: mail ($to,$subject,$message,$headers);
But in order for it to work on a PHPR page, you need to modify it.
PHPRunner uses it own wrapper for the mail() function:
Example: runner_email ($to,$subject,$message,$headers);