URL helper - adding subject data to mailto()

[eluser]aBoy[/eluser]
Hi.

Is there a way to add extra data to a safe_mailto() call?

Code:

$emailAtts = array('subject' => $this->lang->line('contacts_subject'),
        'message' => $this->lang->line('contacts_message'));

...

echo '<p><span class="formLabel">'.$this->lang->line('contacts_email').'</span>'.safe_mailto($d->contactEmail, $d->contactEmail, $emailAtts).'</p>';

The above code won't work for me.