XAMPP comes with MercuryMail. To use it for sending test mails, you can do the followings:
1. Start Mercury Mail from XAMPP control panel.
2. Navigate to Mercury Mail folder in XAMPP installation (Most probably C:\Program Files\xampp\MercuryMail)
3. Double click on mercury.exe and Mercury window will be opened.
4. Go to Configuration -> Local Users
5. Add a user with password (Suppose sajjad)
6. Close this window.
To receive mail configure outlook express with localhost as pop3 and SMTP server.
Hope these information will be helpful.