The GuestBook applet provides a zone where visitors can send you a message by email. Once you have received the mail you decide or not to put the messages in the file "guestbook.txt". The applet displays the messages in this file. As applets can't connect to remote hosts, this applet connects to your local server. So your web server must also be a mail server. To know if it's true open a Telnet session and try this : 'telnet yourhost 25', for example: 'telnet chez.com 25' If it works (no errors) your web server is also a mail server.