mailed-by and Return-Path sent as apache@server.domain.com

I've tried setting the Sender with phpmailer_init action but that did nothing. 

``` php
function mail_return_path( $phpmailer ) {
    $phpmailer->Sender = 'email@domain.com';
}
add_action( 'phpmailer_init', 'mail_return_path' );
```

Any help on how to force that through? 

method used to send email: php
