Problem using wp_mail function in WPMU

I added this line to my wpmu-functions.php file at the end of the newuser_notify_siteadmin function

$headers = 'From: Calvin Micklefinger <>' . "\r\n\\";
   wp_mail('', 'subject', 'message', $headers);

I would have expected that as simple as that is, the email "From" would have said

Calvin Micklefinger <>

As limited as my coding skills are, I really don't see much choice for any other response.

What I got was

"" <>

Why in the Sam Hill is that happening? Where do I look to find a solution? This is also disrupting a very solid and well respected plugin I use.