Creating an email file

[dunnomenaime]

I am trying to create a file on our server with the contents of an email that is sent to users automatically. However, I can't seem to get the syntax right because it keeps dying (displaying message "can't open file"). What is wrong here?

$ourFileName1 = './emails/' . "{$_POST['auth_email']}" . '4800.txt';
			$ourFileHandle1 = fopen($ourFileName1, 'w') or die("can't open file");
 			fwrite($ourFileHandle1, $auth_email_message);