I use the latest WAMP and I get this when I try to send emails:
Warning: mail() [function.mail]: Failed to connect to mailserver at \"localhost\" port 25, ve
I think your mail server (SMTP) outgoing mail server is not configured in your php.ini file.
Have a look at this:
http://email.about.com/od/emailprogrammingtips/qt/Configure_PHP_to_Use_a_Remote_SMTP_Server_for_Sending_Mail.htm
Also hotmail doesn't allow you to use their mailservers. You should use yahoo or gmail.