$headers  = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
$headers .= 'From: '.$wgUser->getEmail().'' . "\r\n";
echo $headers;
				
die();

/*
OUTPUT:

MIME-Version: 1.0 Content-type: text/html; charset=iso-8859-1 From: henderson.mark@gmail.com
*/