Microsoft Outlook can publish a user's free/busy information, but in some situations you might prefer to create your own free/busy server. For example, Microsoft's Office Internet Free/Busy Service requires users to have Microsoft Passports, which you might not want to use. Or, maybe you don't need to offer free/busy information to outside users, so you don't want the information published across the Internet.
Outlook can publish to a free/busy server using HTTP, FTP, or file URLs. If Outlook is configured to publish to an HTTP or file URL that requires authentication, Windows prompts the user for the authentication information. However, this is not the case for FTP servers.
Follow these steps in Outlook to configure the FTP site to enable Outlook to authenticate on the server:
Outlook caches the password for only the current Outlook session, so if the user shuts down Outlook and restarts, he or she will need to enter the password again.
To reenter the password, choose File | Open | Outlook Data File, select the FTP site from the Look In drop-down list, enter the password, and click OK. As above, click Cancel to close the Open Outlook Data File dialog box.