Papercut is a very simple and efficient solution.
Download the zip on http://papercut.codeplex.com/
Papercut is a simple smtp server that take any mail send to localhost and whow them in its GUI.
Start Papercut
Then every time an email is sent I can see it on the gui
I changed nothing on my php.ini
[mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = localhost
; http://php.net/smtp-port
smtp_port = 25
Really really useful and easy to set up.