To use the IMAP features of PHP, you'll need to edit a line or two in your PHP.ini file..
Find the line:
extension_dir = ./
You will need to change that to the directory that stores the DLL's (that came with the PHP archive).
Make sure that the "php_imap.dll" file is in this directory (make sure it's the DLL that came with your PHP.. I got bit by this)
Find the line:
;extension=php_imap.dll
Remove the ";" from the beginning of the line.. Now try any of the IMAP functions _
-Sean